diff --git a/ChangeLog b/ChangeLog
index 5100f30..94e9b9d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2012-01-15  Wolfgang Lux  <wolfgang.lux@gmail.com>
+
+	* Frameworks/StepTalk/STEngine.h (-methodFromSource:...):
+	* Frameworks/StepTalk/STEngine.m (-methodFromSource:...):
+	STMethod is a protocol not a class.
+
 2012-01-15  Wolfgang Lux  <wolfgang.lux@gmail.com>
 
 	* Frameworks/StepTalk/STObjCRuntime.m (STSelectorTypes,
diff --git a/Frameworks/StepTalk/STEngine.h b/Frameworks/StepTalk/STEngine.h
index bd70320..7b9ea05 100644
--- a/Frameworks/StepTalk/STEngine.h
+++ b/Frameworks/StepTalk/STEngine.h
@@ -47,9 +47,9 @@
             inContext:(STContext *)context;
             
 /* Methods */
-- (STMethod *)methodFromSource:(NSString *)sourceString
-                   forReceiver:(id)receiver
-                     inContext:(STContext *)context;
+- (id <STMethod>)methodFromSource:(NSString *)sourceString
+                      forReceiver:(id)receiver
+                        inContext:(STContext *)context;
 - (id)  executeMethod:(id <STMethod>)aMethod
           forReceiver:(id)anObject
         withArguments:(NSArray *)args
diff --git a/Frameworks/StepTalk/STEngine.m b/Frameworks/StepTalk/STEngine.m
index 890af50..fa2ef99 100644
--- a/Frameworks/StepTalk/STEngine.m
+++ b/Frameworks/StepTalk/STEngine.m
@@ -108,9 +108,9 @@ void _STInitMallocZone(void)
     return NO;
 }
 
-- (STMethod *)methodFromSource:(NSString *)sourceString
-                   forReceiver:(id)receiver
-        inContext:(STContext *)env;
+- (id <STMethod>)methodFromSource:(NSString *)sourceString
+                      forReceiver:(id)receiver
+                        inContext:(STContext *)env
 {
     [self subclassResponsibility:_cmd];
     return nil;
@@ -118,7 +118,7 @@ void _STInitMallocZone(void)
 - (id)  executeMethod:(id <STMethod>)aMethod
           forReceiver:(id)anObject
         withArguments:(NSArray *)args
-        inContext:(STContext *)env;
+            inContext:(STContext *)env
 {
     [self subclassResponsibility:_cmd];
     return nil;
diff --git a/Languages/Smalltalk/ChangeLog b/Languages/Smalltalk/ChangeLog
index a7d4b5f..597ea78 100644
--- a/Languages/Smalltalk/ChangeLog
+++ b/Languages/Smalltalk/ChangeLog
@@ -1,3 +1,21 @@
+2012-01-15  Wolfgang Lux  <wolfgang.lux@gmail.com>
+
+    * STBytecodes.h (-data, -length): Declare public methods.
+    * STMethodContext.h: Remove declaration of unused methods, which were
+    not implemented.
+
+    * STCompiler.h (STCompiler, -compiledMethodFromSource:forReceiver:):
+    * STCompiler.m (-compiledMethodFromSource:forReceiver:): STCompiler
+    expects its receiver attribute to be a STScriptObject not just an
+    object that satisfies the weaker STScriptObject protocol.
+
+    * STSmalltalkScriptObject.m: Import NSDictionary and NSKeyValueCoding,
+    whose methods are used in the implementation.
+
+    * STCompiledMethod.h: Import definition of STMethod protocol instead
+    of just declaring it. Gcc 4.6 complains if a protocol whose definition
+    is not visible is used in an interface declaration.
+
 2012-01-15  Wolfgang Lux  <wolfgang.lux@gmail.com>
 
     * STBytecodeInterpreter.m: Remove unnecessary include of Objective-C
diff --git a/Languages/Smalltalk/STBytecodes.h b/Languages/Smalltalk/STBytecodes.h
index c448015..41488ac 100644
--- a/Languages/Smalltalk/STBytecodes.h
+++ b/Languages/Smalltalk/STBytecodes.h
@@ -87,6 +87,8 @@ extern NSString *STDissasembleBytecode(STBytecode bytecode);
     NSData *bytes;
 }
 - (STBytecode)fetchNextBytecodeAtPointer:(unsigned *)pointer;
+- (NSData *) data;
+- (unsigned) length;
 @end
 
 
diff --git a/Languages/Smalltalk/STCompiledMethod.h b/Languages/Smalltalk/STCompiledMethod.h
index 0da5b00..1bd93fc 100644
--- a/Languages/Smalltalk/STCompiledMethod.h
+++ b/Languages/Smalltalk/STCompiledMethod.h
@@ -21,8 +21,7 @@
  */
 
 #import "STCompiledCode.h"
-
-@protocol STMethod;
+#import <StepTalk/STMethod.h>
 
 @class STMessage;
 
diff --git a/Languages/Smalltalk/STCompiler.h b/Languages/Smalltalk/STCompiler.h
index 888c139..b180f56 100644
--- a/Languages/Smalltalk/STCompiler.h
+++ b/Languages/Smalltalk/STCompiler.h
@@ -31,6 +31,7 @@
 @class STCompiledCode;
 @class STCompiledMethod;
 @class STEnvironment;
+@class STScriptObject;
 @class STSourceReader;
 
 @class STCExpression;
@@ -82,7 +83,7 @@ typedef struct _STParserContext
     NSMutableArray   *namedReferences;
     NSMutableArray   *literals;
     
-    id                receiver;
+    STScriptObject   *receiver;
 
     BOOL              isSingleMethod;
     
@@ -109,7 +110,7 @@ typedef struct _STParserContext
 
 - (STCompiledScript *)compileString:(NSString *)aString;
 - (STCompiledMethod *)compileMethodFromSource:(NSString *)aString
-                                  forReceiver:(id <STScriptObject>)receiver;
+                                  forReceiver:(STScriptObject *)receiver;
 
 /*
 - (NSMutableArray *)compileString:(NSString *)string;
diff --git a/Languages/Smalltalk/STCompiler.m b/Languages/Smalltalk/STCompiler.m
index e155e05..1645e9d 100644
--- a/Languages/Smalltalk/STCompiler.m
+++ b/Languages/Smalltalk/STCompiler.m
@@ -180,7 +180,7 @@ extern int STCparse(void *context);
 }
 
 - (STCompiledMethod *)compileMethodFromSource:(NSString *)aString
-                                  forReceiver:(id)receiverObject
+                                  forReceiver:(STScriptObject *)receiverObject
 {
     STCompiledMethod *result;
     NSString         *hackedSource;
diff --git a/Languages/Smalltalk/STMethodContext.h b/Languages/Smalltalk/STMethodContext.h
index e1a6edf..5490e95 100644
--- a/Languages/Smalltalk/STMethodContext.h
+++ b/Languages/Smalltalk/STMethodContext.h
@@ -50,8 +50,5 @@
 - (id)temporaryAtIndex:(unsigned)index;
 - (void)setTemporary:anObject atIndex:(unsigned)index;
 
-- (id)externAtIndex:(unsigned)index;
-- (void)setExtern:anObject atIndex:(unsigned)index;
-
 - (STBytecodes *)bytecodes;
 @end
diff --git a/Languages/Smalltalk/STSmalltalkScriptObject.m b/Languages/Smalltalk/STSmalltalkScriptObject.m
index 0dc4875..0c7b497 100644
--- a/Languages/Smalltalk/STSmalltalkScriptObject.m
+++ b/Languages/Smalltalk/STSmalltalkScriptObject.m
@@ -29,9 +29,11 @@
 
 #import <Foundation/NSArray.h>
 #import <Foundation/NSDebug.h>
+#import <Foundation/NSDictionary.h>
 #import <Foundation/NSMethodSignature.h>
 #import <Foundation/NSString.h>
 #import <Foundation/NSAutoreleasePool.h>
+#import <Foundation/NSKeyValueCoding.h>
 
 #import <StepTalk/NSInvocation+additions.h>
 #import <StepTalk/STEnvironment.h>