diff --git a/ext/gd/libgd/gd_topal.c b/ext/gd/libgd/gd_topal.c
index a92a7acb17a43..2a9fb3d608dc8 100644
--- a/ext/gd/libgd/gd_topal.c
+++ b/ext/gd/libgd/gd_topal.c
@@ -1498,7 +1498,7 @@ static int gdImageTrueColorToPaletteBody (gdImagePtr oim, int dither, int colors
       colorsWanted = maxColors;
     }
   if (!cimP) {
-    nim->pixels = gdCalloc (sizeof (unsigned char *), oim->sy);
+    nim->pixels = gdCalloc (oim->sy, sizeof (unsigned char *));
     if (!nim->pixels)
       {
         /* No can do */
@@ -1506,7 +1506,7 @@ static int gdImageTrueColorToPaletteBody (gdImagePtr oim, int dither, int colors
       }
     for (i = 0; (i < nim->sy); i++)
       {
-        nim->pixels[i] = gdCalloc (sizeof (unsigned char *), oim->sx);
+        nim->pixels[i] = gdCalloc (oim->sx, sizeof (unsigned char *));
         if (!nim->pixels[i])
   	{
   	  goto outOfMemory;
@@ -1514,7 +1514,7 @@ static int gdImageTrueColorToPaletteBody (gdImagePtr oim, int dither, int colors
       }
   }
 
-  cquantize = (my_cquantize_ptr) gdCalloc (sizeof (my_cquantizer), 1);
+  cquantize = (my_cquantize_ptr) gdCalloc (1, sizeof (my_cquantizer));
   if (!cquantize)
     {
       /* No can do */
diff --git a/ext/pdo_mysql/mysql_statement.c b/ext/pdo_mysql/mysql_statement.c
index 765e05e1358e3..c4f86b0e7d320 100644
--- a/ext/pdo_mysql/mysql_statement.c
+++ b/ext/pdo_mysql/mysql_statement.c
@@ -581,7 +581,7 @@ static int pdo_mysql_stmt_fetch(pdo_stmt_t *stmt, enum pdo_fetch_orientation ori
 	}
 
 	if (!S->current_row) {
-		S->current_row = ecalloc(sizeof(zval), stmt->column_count);
+		S->current_row = ecalloc(stmt->column_count, sizeof(zval));
 	}
 	for (unsigned i = 0; i < stmt->column_count; i++) {
 		zval_ptr_dtor_nogc(&S->current_row[i]);
diff --git a/ext/readline/readline.c b/ext/readline/readline.c
index db2776fb27a9a..1bd5e2fd6059a 100644
--- a/ext/readline/readline.c
+++ b/ext/readline/readline.c
@@ -456,7 +456,7 @@ char **php_readline_completion_cb(const char *text, int start, int end)
 				matches = rl_completion_matches(text,_readline_command_generator);
 			} else {
 				/* libedit will read matches[2] */
-				matches = calloc(sizeof(char *), 3);
+				matches = calloc(3, sizeof(char *));
 				if (!matches) {
 					return NULL;
 				}