diff --git a/ext/rpc/com/com.c b/ext/rpc/com/com.c
index 94f8b442e97..8fdee275808 100644
--- a/ext/rpc/com/com.c
+++ b/ext/rpc/com/com.c
@@ -495,7 +495,7 @@ static int com_call(rpc_string method_name, void **data, zval *return_value, int
 	VARIANT *variant_args;
 	VARIANT result;
 	int current_arg, current_variant;
-	char *ErrString;
+	char *ErrString = NULL;
 	TSRMLS_FETCH();
 
 	/* if the length of the name is 0, we are dealing with a pointer to a dispid */
@@ -552,7 +552,7 @@ static int com_call(rpc_string method_name, void **data, zval *return_value, int
 
 static int com_get(rpc_string property_name, zval *return_value, void **data)
 {
-	char *ErrString;
+	char *ErrString = NULL;
 	VARIANT *result;
 	OLECHAR *propname;
 	DISPID dispid;
@@ -610,7 +610,7 @@ static int com_set(rpc_string property_name, zval *value, void **data)
 	DISPID dispid, mydispid = DISPID_PROPERTYPUT;
 	DISPPARAMS dispparams;
 	VARIANT *var;
-	char *error_message, *ErrString;
+	char *error_message, *ErrString = NULL;
 	TSRMLS_FETCH();
 
 	/* obtain property handler */
diff --git a/ext/rpc/com/com_wrapper.c b/ext/rpc/com/com_wrapper.c
index b8af368ce22..49a635e59c1 100644
--- a/ext/rpc/com/com_wrapper.c
+++ b/ext/rpc/com/com_wrapper.c
@@ -125,8 +125,7 @@ ZEND_API HRESULT php_COM_invoke(comval *obj, DISPID dispIdMember, WORD wFlags, D
 						SysFreeString(ExceptInfo.bstrDescription);
 					}
 					
-					*ErrString = emalloc(srclen+desclen+50);
-					zend_sprintf(*ErrString, "<b>Source</b>: %s <b>Description</b>: %s", src, desc);
+					spprintf(ErrString, 0, "<b>Source</b>: %s <b>Description</b>: %s", src, desc);
 					efree(src);
 					efree(desc);
 					
@@ -138,8 +137,7 @@ ZEND_API HRESULT php_COM_invoke(comval *obj, DISPID dispIdMember, WORD wFlags, D
 				break;
 			case DISP_E_PARAMNOTFOUND:
 			case DISP_E_TYPEMISMATCH:
-				*ErrString = emalloc(25);
-				sprintf(*ErrString, "<b>Argument</b>: %d", pDispParams->cArgs-ArgErr+1);
+				spprintf(ErrString, 0, "<b>Argument</b>: %d", pDispParams->cArgs-ArgErr+1);
 				break;
 		}
 	}
@@ -247,7 +245,7 @@ ZEND_API HRESULT php_COM_set(comval *obj, IDispatch FAR* FAR* ppDisp, int cleanu
 
 ZEND_API char *php_COM_error_message(HRESULT hr)
 {
-	void *pMsgBuf;
+	void *pMsgBuf = NULL;
 
 	if (!FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, NULL,
 					   hr, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &pMsgBuf, 0, NULL)) {