diff --git a/src/cff/t2load.c b/src/cff/t2load.c
index 4a7769331..549199147 100644
--- a/src/cff/t2load.c
+++ b/src/cff/t2load.c
@@ -200,7 +200,7 @@
     if ( index && index->count > element )
     {
       /* compute start and end offsets */
-      FT_ULong  off1, off2;
+      FT_ULong  off1, off2 = 0;
 
 
       off1 = index->offsets[element];
diff --git a/src/cid/cidload.c b/src/cid/cidload.c
index 1f7c7aea0..59eeb0b7d 100644
--- a/src/cid/cidload.c
+++ b/src/cid/cidload.c
@@ -267,9 +267,9 @@
   static
   int  is_alpha( char  c )
   {
-    return ( isalnum( c ) ||
-             c == '.'     ||
-             c == '_'     );
+    return ( isalnum( (int)c ) ||
+             c == '.'          ||
+             c == '_'          );
   }
 
 
diff --git a/src/cid/cidparse.c b/src/cid/cidparse.c
index 33d3d8af3..9c4c4aa0e 100644
--- a/src/cid/cidparse.c
+++ b/src/cid/cidparse.c
@@ -439,7 +439,7 @@
   {
     FT_Long   result = 0;
     FT_Byte*  cur    = *cursor;
-    FT_Byte   c, d;
+    FT_Byte   c = '\0', d;
 
 
     for ( ; cur < limit; cur++ )
diff --git a/src/type1z/z1load.c b/src/type1z/z1load.c
index 46478d1a8..59d0e7755 100644
--- a/src/type1z/z1load.c
+++ b/src/type1z/z1load.c
@@ -931,9 +931,9 @@
   static
   int  is_alpha( char c )
   {
-    return ( isalnum( c ) ||
-             ( c == '.' ) ||
-             ( c == '_' ) );
+    return ( isalnum( (int)c ) ||
+             ( c == '.' )      ||
+             ( c == '_' )      );
   }
 
 
diff --git a/src/type1z/z1parse.c b/src/type1z/z1parse.c
index 9bc291387..bb70f5911 100644
--- a/src/type1z/z1parse.c
+++ b/src/type1z/z1parse.c
@@ -451,7 +451,7 @@
   {
     FT_Long   result = 0;
     FT_Byte*  cur    = *cursor;
-    FT_Byte   c, d;
+    FT_Byte   c = '\0', d;
 
 
     for ( ; cur < limit; cur++ )