diff --git a/ChangeLog b/ChangeLog
index 06b4d42..7c6f1c7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2012-01-15  Wolfgang Lux  <wolfgang.lux@gmail.com
+
+	* Frameworks/StepTalk/NSInvocation+additions.m:
+	* Frameworks/StepTalk/STStructure.m:
+	* Modules/ObjectiveC/NSObject+additions.m:
+	* Modules/ObjectiveC/ObjectiveCRuntime.m:
+	Clean up imports removing includes of Objective-C runtime headers.
+	Also replace a few more deprecated Objective-C runtime calls.
+
 2011-04-07  Wolfgang Lux  <wolfgang.lux@gmail.com>
 
 	* Modules/ObjectiveC/ObjectiveCRuntime.m (-allClasses):
diff --git a/Frameworks/StepTalk/NSInvocation+additions.m b/Frameworks/StepTalk/NSInvocation+additions.m
index 02e234b..631098a 100644
--- a/Frameworks/StepTalk/NSInvocation+additions.m
+++ b/Frameworks/StepTalk/NSInvocation+additions.m
@@ -31,8 +31,11 @@
 
 #import <Foundation/NSDebug.h>
 #import <Foundation/NSException.h>
-#import <Foundation/NSValue.h>
+#import <Foundation/NSObjCRuntime.h>
 #import <Foundation/NSString.h>
+#import <Foundation/NSValue.h>
+
+#import <GNUstepBase/GSObjCRuntime.h>
 
 #import "STExterns.h"
 #import "STObjCRuntime.h"
@@ -40,8 +43,6 @@
 #import "STSelector.h"
 #import "STStructure.h"
 
-#import <objc/objc-api.h>
-
 #if 0
 static Class NSNumber_class = nil;
 static Class NSString_class = nil;
@@ -216,7 +217,7 @@ void STGetValueOfTypeFromObject(void *value, const char *type, id anObject)
         // NSLog(@"REGISTERING SELECTOR");
         const char *name = [selectorName cString];
         
-        sel = sel_register_name(name);
+        sel = sel_registerName(name);
 
         if(!sel)
         {
@@ -235,7 +236,7 @@ void STGetValueOfTypeFromObject(void *value, const char *type, id anObject)
     if(requiresRegistration)
     {
         // NSLog(@"REGISTERING SELECTOR TYPES");
-        sel = sel_register_typed_name([selectorName cString], [signature methodReturnType]);
+        sel = GSSelectorFromNameAndTypes([selectorName cString], [signature methodReturnType]);
         // NSLog(@"REGISTERED %@", NSStringFromSelector(sel));
         
     }
@@ -285,10 +286,12 @@ void STGetValueOfTypeFromObject(void *value, const char *type, id anObject)
 - (void)setArgumentAsObject:(id)anObject atIndex:(int)anIndex
 {
     const char *type;
+    NSUInteger size;
     void *value;
     
     type = [[self methodSignature] getArgumentTypeAtIndex:anIndex];
-    value = NSZoneMalloc(STMallocZone,objc_sizeof_type(type));
+    NSGetSizeAndAlignment(type, &size, NULL);
+    value = NSZoneMalloc(STMallocZone, size);
 
     STGetValueOfTypeFromObject(value, type, anObject);
 
@@ -300,12 +303,13 @@ void STGetValueOfTypeFromObject(void *value, const char *type, id anObject)
 - (id)getArgumentAsObjectAtIndex:(int)anIndex
 {
     const char *type;
+    NSUInteger size;
     void *value;
     id    object;
     
     type = [[self methodSignature] getArgumentTypeAtIndex:anIndex];
-
-    value = NSZoneMalloc(STMallocZone,objc_sizeof_type(type));
+    NSGetSizeAndAlignment(type, &size, NULL);
+    value = NSZoneMalloc(STMallocZone, size);
     [self getArgument:value atIndex:anIndex];
 
     object = STObjectFromValueOfType(value,type);
diff --git a/Frameworks/StepTalk/STStructure.m b/Frameworks/StepTalk/STStructure.m
index 23b879d..8c1a46a 100644
--- a/Frameworks/StepTalk/STStructure.m
+++ b/Frameworks/StepTalk/STStructure.m
@@ -29,13 +29,12 @@
 #import "STExterns.h"
 #import <Foundation/NSArray.h>
 #import <Foundation/NSException.h>
+#import <Foundation/NSObjCRuntime.h>
 #import <Foundation/NSString.h>
 #import <Foundation/NSValue.h>
 #import <Foundation/NSDebug.h>
 #import "NSInvocation+additions.h"
 
-#import <objc/objc-api.h>
-
 @implementation STStructure
 + structureWithValue:(void *)value type:(const char*)type
 {
@@ -72,10 +71,10 @@
 
 - initWithValue:(void *)value type:(const char*)type
 {
-    const char *nameBeg;
-    int offset = 0;
-    int align;
-    int rem;
+    const char *nameBeg, *nextType;
+    NSUInteger  offset = 0;
+    NSUInteger  size, align;
+    NSUInteger  rem;
     
 
     self = [super init];
@@ -95,22 +94,18 @@
     
     while(*type != _C_STRUCT_E)
     {
-        [fields addObject:STObjectFromValueOfType(((char *)value)+offset,type)];
+        nextType = NSGetSizeAndAlignment(type, &size, &align);
 
-        offset += objc_sizeof_type(type);                                 
-        type = objc_skip_typespec(type);
-
-        if(*type == _C_STRUCT_E)
-        {
-            break;
-        }
-            
-        align = objc_alignof_type(type);
         rem = offset % align;
         if(rem != 0)
         {
             offset += align - rem;
         }
+
+        [fields addObject:STObjectFromValueOfType(((char *)value)+offset,type)];
+
+        offset += size;                                 
+	type = nextType;
     }
 
     return self;
@@ -126,33 +121,31 @@
 - (void)getValue:(void *)value
 {
     const char *type = [structType cString];
-    int offset=0;
-    int align;
-    int rem;
-    int i = 0;
+    const char *nextType;
+    NSUInteger  offset = 0;
+    NSUInteger  size, align;
+    NSUInteger  rem;
+    NSUInteger  i = 0;
     
     type++;
     while (*type != _C_STRUCT_E && *type++ != '=');
 
     while(*type != _C_STRUCT_E)
     {
-        STGetValueOfTypeFromObject((void *)((char*)value+offset),
-                                   type,
-                                   [fields objectAtIndex:i++]);
+        nextType = NSGetSizeAndAlignment(type, &size, &align);
 
-        offset += objc_sizeof_type(type);                                 
-        type = objc_skip_typespec(type);
-
-        if(*type == _C_STRUCT_E)
-        {
-            break;
-        }
-        align = objc_alignof_type(type);
         rem = offset % align;
         if(rem != 0)
         {
             offset += align - rem;
         }
+
+        STGetValueOfTypeFromObject((char*)value+offset,
+                                   type,
+                                   [fields objectAtIndex:i++]);
+
+        offset += size;                                 
+	type = nextType;
     }
 }
 
diff --git a/Languages/Smalltalk/ChangeLog b/Languages/Smalltalk/ChangeLog
index f876ab2..a7d4b5f 100644
--- a/Languages/Smalltalk/ChangeLog
+++ b/Languages/Smalltalk/ChangeLog
@@ -1,3 +1,8 @@
+2012-01-15  Wolfgang Lux  <wolfgang.lux@gmail.com>
+
+    * STBytecodeInterpreter.m: Remove unnecessary include of Objective-C
+    runtime header.
+
 2011-01-20  Wolfgang Lux  <wolfgang.lux@gmail.com>
 
     * SmalltalkInfo.plist: Add missing semicolons at end of plist
diff --git a/Languages/Smalltalk/STBytecodeInterpreter.m b/Languages/Smalltalk/STBytecodeInterpreter.m
index e25a735..6596f67 100644
--- a/Languages/Smalltalk/STBytecodeInterpreter.m
+++ b/Languages/Smalltalk/STBytecodeInterpreter.m
@@ -50,8 +50,6 @@
 #import <Foundation/NSInvocation.h>
 #import <Foundation/NSValue.h>
 
-#import  <objc/encoding.h>
-
 @interface STBytecodeInterpreter(STPrivateMethods)
 - (short)fetchBytecode;
 - (BOOL)dispatchBytecode:(STBytecode)bytecode;
diff --git a/Modules/ObjectiveC/NSObject+additions.m b/Modules/ObjectiveC/NSObject+additions.m
index 5976c53..e946e2c 100644
--- a/Modules/ObjectiveC/NSObject+additions.m
+++ b/Modules/ObjectiveC/NSObject+additions.m
@@ -26,8 +26,6 @@
 
 #import "NSObject+additions.h"
 
-#import <objc/objc-api.h>
-
 #import <Foundation/NSArray.h>
 #import <Foundation/NSString.h>
 
diff --git a/Modules/ObjectiveC/ObjectiveCRuntime.m b/Modules/ObjectiveC/ObjectiveCRuntime.m
index 21166c5..4698bd6 100644
--- a/Modules/ObjectiveC/ObjectiveCRuntime.m
+++ b/Modules/ObjectiveC/ObjectiveCRuntime.m
@@ -28,8 +28,6 @@
 
 #import "NSObject+additions.h"
 
-#import <objc/objc-api.h>
-
 #import <StepTalk/STObjCRuntime.h>
 #import <StepTalk/STSelector.h>