diff --git a/reactos/dll/win32/gdi32/include/gdi32p.h b/reactos/dll/win32/gdi32/include/gdi32p.h
index 3fc5f0da8c8..f71d4847146 100644
--- a/reactos/dll/win32/gdi32/include/gdi32p.h
+++ b/reactos/dll/win32/gdi32/include/gdi32p.h
@@ -31,7 +31,8 @@ typedef INT
 #define METAFILE_DISK   2
 
 /* MACRO ********************************************************************/
-#define ROP_USES_SOURCE(Rop)   ((Rop << 2) ^ Rop) & 0xCC0000
+
+#define ROP_USES_SOURCE(Rop)   (((Rop) << 2 ^ Rop) & 0xCC0000)
 
 /* TYPES *********************************************************************/
 
diff --git a/reactos/dll/win32/user32/controls/combo.c b/reactos/dll/win32/user32/controls/combo.c
index e8383d76426..14e358a1371 100644
--- a/reactos/dll/win32/user32/controls/combo.c
+++ b/reactos/dll/win32/user32/controls/combo.c
@@ -783,7 +783,7 @@ static void CBPaintText(
 	 clipRegion=NULL;
        }
 
-       if (!IsWindowEnabled(lphc->self) & WS_DISABLED) itemState |= ODS_DISABLED;
+       if (!(IsWindowEnabled(lphc->self) & WS_DISABLED)) itemState |= ODS_DISABLED;
 
        dis.CtlType	= ODT_COMBOBOX;
        dis.CtlID	= ctlid;
diff --git a/reactos/dll/win32/user32/misc/ddeclient.c b/reactos/dll/win32/user32/misc/ddeclient.c
index d9263dc01f8..9d8c989e84f 100644
--- a/reactos/dll/win32/user32/misc/ddeclient.c
+++ b/reactos/dll/win32/user32/misc/ddeclient.c
@@ -811,7 +811,7 @@ static WDML_QUEUE_STATE WDML_HandleTerminateReply(WDML_CONV* pConv, MSG* msg, WD
 	FIXME("hmmm shouldn't happen\n");
 	return WDML_QS_PASS;
     }
-    if (!pConv->instance->CBFflags & CBF_SKIP_DISCONNECTS)
+    if (!(pConv->instance->CBFflags & CBF_SKIP_DISCONNECTS))
     {
 	WDML_InvokeCallback(pConv->instance, XTYP_DISCONNECT, 0, (HCONV)pConv,
 			    0, 0, 0, 0, (pConv->wStatus & ST_ISSELF) ? 1 : 0);
@@ -894,7 +894,7 @@ static WDML_QUEUE_STATE WDML_HandleIncomingTerminate(WDML_CONV* pConv, MSG* msg,
 	return WDML_QS_PASS;
 
     pConv->wStatus |= ST_TERMINATED;
-    if (!pConv->instance->CBFflags & CBF_SKIP_DISCONNECTS)
+    if (!(pConv->instance->CBFflags & CBF_SKIP_DISCONNECTS))
     {
 	WDML_InvokeCallback(pConv->instance, XTYP_DISCONNECT, 0, (HCONV)pConv,
 			    0, 0, 0, 0, (pConv->wStatus & ST_ISSELF) ? 1 : 0);