diff --git a/objectivec/GPBUtilities_PackagePrivate.h b/objectivec/GPBUtilities_PackagePrivate.h
index cac551f..ed424ce 100644
--- a/objectivec/GPBUtilities_PackagePrivate.h
+++ b/objectivec/GPBUtilities_PackagePrivate.h
@@ -50,9 +50,20 @@
 
 // These two are used to inject a runtime check for version mismatch into the
 // generated sources to make sure they are linked with a supporting runtime.
+void GPBCheckRuntimeVersionSupport(int32_t objcRuntimeVersion);
+GPB_INLINE void GPB_DEBUG_CHECK_RUNTIME_VERSIONS() {
+  // NOTE: By being inline here, this captures the value from the library's
+  // headers at the time the generated code was compiled.
+#if defined(DEBUG) && DEBUG
+  GPBCheckRuntimeVersionSupport(GOOGLE_PROTOBUF_OBJC_VERSION);
+#endif
+}
+
+// Legacy version of the checks, remove when GOOGLE_PROTOBUF_OBJC_GEN_VERSION
+// goes away (see more info in GPBBootstrap.h).
 void GPBCheckRuntimeVersionInternal(int32_t version);
 GPB_INLINE void GPBDebugCheckRuntimeVersion() {
-#if DEBUG
+#if defined(DEBUG) && DEBUG
   GPBCheckRuntimeVersionInternal(GOOGLE_PROTOBUF_OBJC_GEN_VERSION);
 #endif
 }
@@ -96,7 +107,7 @@
 // negative values must be sign-extended to 64 bits to be varint encoded,
 // thus always taking 10 bytes on the wire.)
 GPB_INLINE int32_t GPBDecodeZigZag32(uint32_t n) {
-  return GPBLogicalRightShift32(n, 1) ^ -(n & 1);
+  return (int32_t)(GPBLogicalRightShift32((int32_t)n, 1) ^ -((int32_t)(n) & 1));
 }
 
 // Decode a ZigZag-encoded 64-bit value.  ZigZag encodes signed integers
@@ -104,7 +115,7 @@
 // negative values must be sign-extended to 64 bits to be varint encoded,
 // thus always taking 10 bytes on the wire.)
 GPB_INLINE int64_t GPBDecodeZigZag64(uint64_t n) {
-  return GPBLogicalRightShift64(n, 1) ^ -(n & 1);
+  return (int64_t)(GPBLogicalRightShift64((int64_t)n, 1) ^ -((int64_t)(n) & 1));
 }
 
 // Encode a ZigZag-encoded 32-bit value.  ZigZag encodes signed integers
@@ -113,7 +124,7 @@
 // thus always taking 10 bytes on the wire.)
 GPB_INLINE uint32_t GPBEncodeZigZag32(int32_t n) {
   // Note:  the right-shift must be arithmetic
-  return (n << 1) ^ (n >> 31);
+  return ((uint32_t)n << 1) ^ (uint32_t)(n >> 31);
 }
 
 // Encode a ZigZag-encoded 64-bit value.  ZigZag encodes signed integers
@@ -122,9 +133,13 @@
 // thus always taking 10 bytes on the wire.)
 GPB_INLINE uint64_t GPBEncodeZigZag64(int64_t n) {
   // Note:  the right-shift must be arithmetic
-  return (n << 1) ^ (n >> 63);
+  return ((uint64_t)n << 1) ^ (uint64_t)(n >> 63);
 }
 
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wswitch-enum"
+#pragma clang diagnostic ignored "-Wdirect-ivar-access"
+
 GPB_INLINE BOOL GPBDataTypeIsObject(GPBDataType type) {
   switch (type) {
     case GPBDataTypeBytes:
@@ -185,7 +200,9 @@
 }
 
 void GPBMaybeClearOneof(GPBMessage *self, GPBOneofDescriptor *oneof,
-                        uint32_t fieldNumberNotToClear);
+                        int32_t oneofHasIndex, uint32_t fieldNumberNotToClear);
+
+#pragma clang diagnostic pop
 
 //%PDDM-DEFINE GPB_IVAR_SET_DECL(NAME, TYPE)
 //%void GPBSet##NAME##IvarWithFieldInternal(GPBMessage *self,
@@ -292,7 +309,8 @@
 
 // A series of selectors that are used solely to get @encoding values
 // for them by the dynamic protobuf runtime code. See
-// GPBMessageEncodingForSelector for details.
+// GPBMessageEncodingForSelector for details. GPBRootObject conforms to
+// the protocol so that it is encoded in the Objective C runtime.
 @protocol GPBMessageSignatureProtocol
 @optional
 
@@ -328,4 +346,6 @@
 + (id)getClassValue;
 @end
 
+BOOL GPBClassHasSel(Class aClass, SEL sel);
+
 CF_EXTERN_C_END