diff --git a/targets/TARGET_STM/TARGET_STM32F4/trng_api.c b/targets/TARGET_STM/TARGET_STM32F4/trng_api.c
deleted file mode 100644
index 54ac041e534..00000000000
--- a/targets/TARGET_STM/TARGET_STM32F4/trng_api.c
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- *  Hardware entropy collector for the STM32F4 family
- *
- *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
- *  SPDX-License-Identifier: Apache-2.0
- *
- *  Licensed under the Apache License, Version 2.0 (the "License"); you may
- *  not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *  http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *
- */
-
-#if defined(DEVICE_TRNG)
-
-#if defined(TARGET_STM32F405xx) || defined(TARGET_STM32F415xx) || defined(TARGET_STM32F407xx) || defined(TARGET_STM32F417xx) ||\
-    defined(TARGET_STM32F427xx) || defined(TARGET_STM32F437xx) || defined(TARGET_STM32F429xx) || defined(TARGET_STM32F439xx) ||\
-    defined(TARGET_STM32F410Tx) || defined(TARGET_STM32F410Cx) || defined(TARGET_STM32F410Rx) || defined(TARGET_STM32F469xx) ||\
-    defined(TARGET_STM32F479xx)
-#include <stdlib.h>
-#include "cmsis.h"
-#include "trng_api.h"
-
-/** trng_get_byte
- *  @brief Get one byte of entropy from the RNG, assuming it is up and running.
- *  @param obj TRNG obj
- *  @param pointer to the hardware generated random byte.
- */
-static void trng_get_byte(trng_t *obj, unsigned char *byte )
-{
-    *byte = (unsigned char)HAL_RNG_GetRandomNumber(&obj->handle);
-}
-
-void trng_init(trng_t *obj)
-{
-    /* RNG Peripheral clock enable */
-    __HAL_RCC_RNG_CLK_ENABLE();
-
-    /* Initialize RNG instance */
-    obj->handle.Instance = RNG;
-    HAL_RNG_Init(&obj->handle);
-
-}
-
-void trng_free(trng_t *obj)
-{
-    /*Disable the RNG peripheral */
-    HAL_RNG_DeInit(&obj->handle);
-    /* RNG Peripheral clock disable - assume we're the only users of RNG  */
-    __HAL_RCC_RNG_CLK_DISABLE();
-}
-
-int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
-{
-    int ret;
-
-    /* Get Random byte */
-    for( uint32_t i = 0; i < length; i++ ){
-        trng_get_byte(obj, output + i );
-    }
-
-    *output_length = length;
-    /* Just be extra sure that we didn't do it wrong */
-    if( ( __HAL_RNG_GET_FLAG(&obj->handle, (RNG_FLAG_CECS | RNG_FLAG_SECS)) ) != 0 ) {
-        ret = -1;
-    } else {
-        ret = 0;
-    }
-
-    return( ret );
-}
-#endif /* STM32F405xx || STM32F415xx || STM32F407xx || STM32F417xx || STM32F427xx || STM32F437xx ||\
-          STM32F429xx || STM32F439xx || STM32F410xx || STM32F469xx || STM32F479xx */
-
-#endif
diff --git a/targets/TARGET_STM/TARGET_STM32L0/TARGET_DISCO_L053C8/objects.h b/targets/TARGET_STM/TARGET_STM32L0/TARGET_DISCO_L053C8/objects.h
index b464a5f2e79..3932d461284 100644
--- a/targets/TARGET_STM/TARGET_STM32L0/TARGET_DISCO_L053C8/objects.h
+++ b/targets/TARGET_STM/TARGET_STM32L0/TARGET_DISCO_L053C8/objects.h
@@ -84,6 +84,10 @@ struct i2c_s {
     I2CName  i2c;
 };
 
+struct trng_s {
+    RNG_HandleTypeDef handle;
+};
+
 #include "common_objects.h"
 #include "gpio_object.h"
 
diff --git a/targets/TARGET_STM/TARGET_STM32L0/TARGET_NUCLEO_L073RZ/objects.h b/targets/TARGET_STM/TARGET_STM32L0/TARGET_NUCLEO_L073RZ/objects.h
index b464a5f2e79..3932d461284 100644
--- a/targets/TARGET_STM/TARGET_STM32L0/TARGET_NUCLEO_L073RZ/objects.h
+++ b/targets/TARGET_STM/TARGET_STM32L0/TARGET_NUCLEO_L073RZ/objects.h
@@ -84,6 +84,10 @@ struct i2c_s {
     I2CName  i2c;
 };
 
+struct trng_s {
+    RNG_HandleTypeDef handle;
+};
+
 #include "common_objects.h"
 #include "gpio_object.h"
 
diff --git a/targets/TARGET_STM/TARGET_STM32L4/TARGET_DISCO_L476VG/objects.h b/targets/TARGET_STM/TARGET_STM32L4/TARGET_DISCO_L476VG/objects.h
index 7f1ca3c87d6..20556881d81 100644
--- a/targets/TARGET_STM/TARGET_STM32L4/TARGET_DISCO_L476VG/objects.h
+++ b/targets/TARGET_STM/TARGET_STM32L4/TARGET_DISCO_L476VG/objects.h
@@ -90,6 +90,10 @@ struct can_s {
     int index;
 };
 
+struct trng_s {
+    RNG_HandleTypeDef handle;
+};
+
 #include "common_objects.h"
 #include "gpio_object.h"
 
diff --git a/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L432KC/objects.h b/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L432KC/objects.h
index 3aa688ef3a0..c3407b008d6 100644
--- a/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L432KC/objects.h
+++ b/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L432KC/objects.h
@@ -90,6 +90,10 @@ struct can_s {
     int index;
 };
 
+struct trng_s {
+    RNG_HandleTypeDef handle;
+};
+
 #include "gpio_object.h"
 #include "common_objects.h"
 
diff --git a/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L476RG/objects.h b/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L476RG/objects.h
index 7f1ca3c87d6..20556881d81 100644
--- a/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L476RG/objects.h
+++ b/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L476RG/objects.h
@@ -90,6 +90,10 @@ struct can_s {
     int index;
 };
 
+struct trng_s {
+    RNG_HandleTypeDef handle;
+};
+
 #include "common_objects.h"
 #include "gpio_object.h"
 
diff --git a/targets/TARGET_STM/TARGET_STM32F7/trng_api.c b/targets/TARGET_STM/trng_api.c
similarity index 78%
rename from targets/TARGET_STM/TARGET_STM32F7/trng_api.c
rename to targets/TARGET_STM/trng_api.c
index ef3595e9b14..f10bf69e06e 100644
--- a/targets/TARGET_STM/TARGET_STM32F7/trng_api.c
+++ b/targets/TARGET_STM/trng_api.c
@@ -1,5 +1,5 @@
 /*
- *  Hardware entropy collector for the STM32F7 family
+ *  Hardware entropy collector for the STM32 families
  *
  *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
@@ -26,6 +26,7 @@
 
 /** trng_get_byte
  *  @brief Get one byte of entropy from the RNG, assuming it is up and running.
+ *  @param obj TRNG obj
  *  @param pointer to the hardware generated random byte.
  */
 static void trng_get_byte(trng_t *obj, unsigned char *byte )
@@ -35,6 +36,15 @@ static void trng_get_byte(trng_t *obj, unsigned char *byte )
 
 void trng_init(trng_t *obj)
 {
+#if defined(TARGET_STM32L4)
+    RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;
+
+    /*Select PLLQ output as RNG clock source */
+    PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_RNG;
+    PeriphClkInitStruct.RngClockSelection = RCC_RNGCLKSOURCE_PLL;
+    HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
+#endif
+
     /* RNG Peripheral clock enable */
     __HAL_RCC_RNG_CLK_ENABLE();
 
@@ -42,6 +52,9 @@ void trng_init(trng_t *obj)
     obj->handle.Instance = RNG;
     HAL_RNG_Init(&obj->handle);
 
+    /* first random number generated after setting the RNGEN bit should not be used */
+    HAL_RNG_GetRandomNumber(&obj->handle);
+
 }
 
 void trng_free(trng_t *obj)
diff --git a/targets/targets.json b/targets/targets.json
index 6de5fe0efd4..055c58bc6a6 100644
--- a/targets/targets.json
+++ b/targets/targets.json
@@ -915,11 +915,11 @@
         "supported_form_factors": ["ARDUINO", "MORPHO"],
         "core": "Cortex-M0+",
         "default_toolchain": "ARM",
-        "extra_labels": ["STM", "STM32L0", "STM32L073RZ"],
+        "extra_labels": ["STM", "STM32L0", "STM32L073RZ", "STM32L073xx"],
         "supported_toolchains": ["ARM", "uARM", "GCC_ARM", "IAR"],
         "inherits": ["Target"],
         "detect_code": ["0760"],
-        "device_has": ["ANALOGIN", "ANALOGOUT", "I2C", "I2CSLAVE", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_FC", "SERIAL_ASYNCH", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES"],
+        "device_has": ["ANALOGIN", "ANALOGOUT", "I2C", "I2CSLAVE", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_FC", "SERIAL_ASYNCH", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES", "TRNG"],
         "release_versions": ["2", "5"],
         "device_name": "STM32L073RZ"
     },
@@ -943,7 +943,7 @@
         "supported_toolchains": ["ARM", "uARM", "IAR", "GCC_ARM"],
         "inherits": ["Target"],
         "detect_code": ["0770"],
-        "device_has": ["ANALOGIN", "ANALOGOUT", "I2C", "I2CSLAVE", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "CAN", "STDIO_MESSAGES"],
+        "device_has": ["ANALOGIN", "ANALOGOUT", "I2C", "I2CSLAVE", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "CAN", "STDIO_MESSAGES", "TRNG"],
         "release_versions": ["2", "5"],
         "device_name" : "STM32L432KC"
     },
@@ -955,7 +955,7 @@
         "supported_toolchains": ["ARM", "uARM", "IAR", "GCC_ARM"],
         "inherits": ["Target"],
         "detect_code": ["0765"],
-        "device_has": ["ANALOGIN", "ANALOGOUT", "CAN", "I2C", "I2CSLAVE", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_ASYNCH", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES"],
+        "device_has": ["ANALOGIN", "ANALOGOUT", "CAN", "I2C", "I2CSLAVE", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_ASYNCH", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES", "TRNG"],
         "release_versions": ["2", "5"],
         "device_name": "stm32l476rg"
     },
@@ -1100,7 +1100,7 @@
         "extra_labels": ["STM", "STM32L4", "STM32L476VG"],
         "supported_toolchains": ["ARM", "uARM", "IAR", "GCC_ARM"],
         "detect_code": ["0820"],
-        "device_has": ["ANALOGIN", "ANALOGOUT", "CAN", "I2C", "I2CSLAVE", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES"],
+        "device_has": ["ANALOGIN", "ANALOGOUT", "CAN", "I2C", "I2CSLAVE", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES", "TRNG"],
         "release_versions": ["2", "5"],
         "device_name": "stm32l476vg"
     },