diff --git a/libsrc/runtime/incaxy.s b/libsrc/runtime/incaxy.s
index 0ee7d879f..faeacf709 100644
--- a/libsrc/runtime/incaxy.s
+++ b/libsrc/runtime/incaxy.s
@@ -1,7 +1,7 @@
 ;
 ; Ullrich von Bassewitz, 05.08.1998
 ;
-; CC65 runtime: Increment ax by valie in y
+; CC65 runtime: Increment ax by value in y
 ;
 
         .export         incaxy, incax4
diff --git a/libsrc/runtime/incsp2.s b/libsrc/runtime/incsp2.s
index 067154b86..0ed0ffcdf 100644
--- a/libsrc/runtime/incsp2.s
+++ b/libsrc/runtime/incsp2.s
@@ -2,7 +2,7 @@
 ; Ullrich von Bassewitz, 25.10.2000
 ;
 ; CC65 runtime: Increment the stackpointer by 2. For performance reasons,
-;               this modules does also contain the popax function.
+;               this module also contains the popax function.
 
         .export         popax, incsp2
         .importzp       sp
diff --git a/libsrc/runtime/jmpvec.s b/libsrc/runtime/jmpvec.s
index ed77a0789..29a18b1db 100644
--- a/libsrc/runtime/jmpvec.s
+++ b/libsrc/runtime/jmpvec.s
@@ -1,7 +1,7 @@
 ;
 ; Ullrich von Bassewitz, 2002-12-26
 ;
-; CC65 runtime: Jump vector that resides in the data segment so it's address 
+; CC65 runtime: Jump vector that resides in the data segment so its address
 ; may be patched at runtime.
 ;
 
diff --git a/libsrc/runtime/mulax3.s b/libsrc/runtime/mulax3.s
index c35b05dcc..472bc60ec 100644
--- a/libsrc/runtime/mulax3.s
+++ b/libsrc/runtime/mulax3.s
@@ -1,7 +1,7 @@
 ;
 ; Ullrich von Bassewitz, 04.10.2001
 ;
-; CC65 runtime: Multiply the primary register
+; CC65 runtime: Multiply the primary register by 3
 ;
 
         .export         mulax3
diff --git a/libsrc/runtime/mulax5.s b/libsrc/runtime/mulax5.s
index 9af599806..7e5ed11d9 100644
--- a/libsrc/runtime/mulax5.s
+++ b/libsrc/runtime/mulax5.s
@@ -1,7 +1,7 @@
 ;
 ; Ullrich von Bassewitz, 04.10.2001
 ;
-; CC65 runtime: Multiply the primary register
+; CC65 runtime: Multiply the primary register by 5
 ;
 
         .export         mulax5