diff --git a/examples/platforms/cc2538/entropy.c b/examples/platforms/cc2538/entropy.c
index 6b6899049..2c50586e5 100644
--- a/examples/platforms/cc2538/entropy.c
+++ b/examples/platforms/cc2538/entropy.c
@@ -41,12 +41,15 @@
 
 static void generateRandom(uint8_t *aOutput, uint16_t aOutputLength)
 {
+    uint32_t frmctrl0;
+
     HWREG(SOC_ADC_ADCCON1) &= ~(SOC_ADC_ADCCON1_RCTRL1 | SOC_ADC_ADCCON1_RCTRL0);
     HWREG(SYS_CTRL_RCGCRFC) = SYS_CTRL_RCGCRFC_RFC0;
 
     while (HWREG(SYS_CTRL_RCGCRFC) != SYS_CTRL_RCGCRFC_RFC0)
         ;
 
+    frmctrl0                    = HWREG(RFCORE_XREG_FRMCTRL0);
     HWREG(RFCORE_XREG_FRMCTRL0) = RFCORE_XREG_FRMCTRL0_INFINITY_RX;
     HWREG(RFCORE_SFR_RFST)      = RFCORE_SFR_RFST_INSTR_RXON;
 
@@ -64,7 +67,8 @@ static void generateRandom(uint8_t *aOutput, uint16_t aOutputLength)
         }
     }
 
-    HWREG(RFCORE_SFR_RFST) = RFCORE_SFR_RFST_INSTR_RFOFF;
+    HWREG(RFCORE_SFR_RFST)      = RFCORE_SFR_RFST_INSTR_RFOFF;
+    HWREG(RFCORE_XREG_FRMCTRL0) = frmctrl0;
 }
 
 void cc2538RandomInit(void)