diff --git a/xpcom/reflect/xptcall/src/md/unix/xptcinvoke_ppc_aix.cpp b/xpcom/reflect/xptcall/src/md/unix/xptcinvoke_ppc_aix.cpp
index 519b3a7f2c2..138c252d7e1 100644
--- a/xpcom/reflect/xptcall/src/md/unix/xptcinvoke_ppc_aix.cpp
+++ b/xpcom/reflect/xptcall/src/md/unix/xptcinvoke_ppc_aix.cpp
@@ -99,16 +99,17 @@ invoke_count_words(PRUint32 paramCount, nsXPTCVariant* s)
 }
 
 extern "C" void
-invoke_copy_to_stack(PRUint32* d, PRUint32 paramCount, nsXPTCVariant* s)
+invoke_copy_to_stack(PRUint32* d, PRUint32 paramCount, nsXPTCVariant* s, double *fprData)
 {
 /*
     We need to copy the parameters for this function to locals and use them
     from there since the parameters occupy the same stack space as the stack
     we're trying to populate.
 */
-    uint32 *l_d = d;
+    PRUint32 *l_d = d;
     nsXPTCVariant *l_s = s;
-    uint32 l_paramCount = paramCount;
+    PRUint32 l_paramCount = paramCount, fpCount = 0;
+    double *l_fprData = fprData;
 
     typedef struct {
         uint32 hi;
@@ -129,14 +130,24 @@ invoke_copy_to_stack(PRUint32* d, PRUint32 paramCount, nsXPTCVariant* s)
         case nsXPTType::T_I16    : *((int32*)  l_d) = l_s->val.i16;         break;
         case nsXPTType::T_I32    : *((int32*)  l_d) = l_s->val.i32;         break;
         case nsXPTType::T_I64    : 
-        case nsXPTType::T_U64    : 
-        case nsXPTType::T_DOUBLE : *((uint32*) l_d++) = ((DU *)l_s)->hi;
-                                   *((uint32*) l_d) = ((DU *)l_s)->lo;
-                                   break;
+        case nsXPTType::T_U64    :
+            *((uint32*) l_d++) = ((DU *)l_s)->hi;
+            *((uint32*) l_d) = ((DU *)l_s)->lo;
+            break;
+        case nsXPTType::T_DOUBLE :
+            *((uint32*) l_d++) = ((DU *)l_s)->hi;
+            *((uint32*) l_d) = ((DU *)l_s)->lo;
+            if(fpCount < 13)
+                l_fprData[fpCount++] = l_s->val.d;
+            break;
         case nsXPTType::T_U8     : *((uint32*) l_d) = l_s->val.u8;          break;
         case nsXPTType::T_U16    : *((uint32*) l_d) = l_s->val.u16;         break;
         case nsXPTType::T_U32    : *((uint32*) l_d) = l_s->val.u32;         break;
-        case nsXPTType::T_FLOAT  : *((float*)  l_d) = l_s->val.f;           break;
+        case nsXPTType::T_FLOAT  :
+            *((float*)  l_d) = l_s->val.f;
+            if(fpCount < 13)
+                l_fprData[fpCount++] = l_s->val.f;
+            break;
         case nsXPTType::T_BOOL   : *((PRBool*) l_d) = l_s->val.b;           break;
         case nsXPTType::T_CHAR   : *((uint32*) l_d) = l_s->val.c;           break;
         case nsXPTType::T_WCHAR  : *((int32*)  l_d) = l_s->val.wc;          break;