diff --git a/code/script/scriptcompiler.cpp b/code/script/scriptcompiler.cpp
index a7acb868..eef31697 100644
--- a/code/script/scriptcompiler.cpp
+++ b/code/script/scriptcompiler.cpp
@@ -77,7 +77,7 @@ unsigned char ScriptCompiler::PrevOpcode()
     return prev_opcodes[prev_opcode_pos].opcode;
 }
 
-char ScriptCompiler::PrevVarStackOffset()
+signed char ScriptCompiler::PrevVarStackOffset()
 {
     return prev_opcodes[prev_opcode_pos].VarStackOffset;
 }
diff --git a/code/script/scriptcompiler.h b/code/script/scriptcompiler.h
index 81e85be2..42203b01 100644
--- a/code/script/scriptcompiler.h
+++ b/code/script/scriptcompiler.h
@@ -77,7 +77,7 @@ public:
     void Reset();
 
     unsigned char PrevOpcode();
-    char          PrevVarStackOffset();
+    signed char   PrevVarStackOffset();
     void          AbsorbPrevOpcode();
     void          ClearPrevOpcode();
     void          AccumulatePrevOpcode(int opcode, int iVarStackOffset);
diff --git a/code/script/scriptopcodes.h b/code/script/scriptopcodes.h
index 62ade8fd..ddddfb43 100644
--- a/code/script/scriptopcodes.h
+++ b/code/script/scriptopcodes.h
@@ -50,7 +50,7 @@ typedef struct {
 
 typedef struct {
     unsigned char opcode;
-    char          VarStackOffset;
+    signed char   VarStackOffset;
 } opcode_info_t;
 
 typedef enum {