diff --git a/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha1_alt.c b/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha1_alt.c
index ddb0dc8178..a8d0254310 100644
--- a/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha1_alt.c
+++ b/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha1_alt.c
@@ -90,7 +90,7 @@ int mbedtls_sha1_update_ret( mbedtls_sha1_context *ctx,
     SHA1_VALIDATE_RET( ilen == 0 || input != NULL );
 
     if (ilen == 0)
-        return;
+        return (0);
 
     return cy_hw_sha_update(&ctx->obj, &ctx->hashState, input, ilen);
 }
diff --git a/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha256_alt.c b/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha256_alt.c
index daf89404b3..efb8552653 100644
--- a/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha256_alt.c
+++ b/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha256_alt.c
@@ -90,8 +90,8 @@ int mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx, const unsigned char
     SHA256_VALIDATE_RET( ilen == 0 || input != NULL );
 
     if (ilen == 0)
-        return;
-    
+        return (0);
+
     return cy_hw_sha_update(&ctx->obj, &ctx->hashState, (uint8_t *)input, ilen);
 }
 
diff --git a/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha512_alt.c b/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha512_alt.c
index dd6f5fed43..5d9cf48a3c 100644
--- a/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha512_alt.c
+++ b/features/mbedtls/targets/TARGET_Cypress/TARGET_PSOC6/sha512_alt.c
@@ -88,9 +88,9 @@ int mbedtls_sha512_update_ret( mbedtls_sha512_context *ctx, const unsigned char
 {
     SHA512_VALIDATE_RET( ctx != NULL );
     SHA512_VALIDATE_RET( ilen == 0 || input != NULL );
-    
+
     if (ilen == 0)
-        return;
+        return (0);
 
     return cy_hw_sha_update(&ctx->obj, &ctx->hashState, input, ilen);
 }