diff --git a/libsrc/telestrat/read.s b/libsrc/telestrat/read.s
index b89f246cc..1d2315dce 100644
--- a/libsrc/telestrat/read.s
+++ b/libsrc/telestrat/read.s
@@ -31,12 +31,12 @@
         BRK_TELEMON     XFREAD
         ;  compute nb of bytes read
         sec
-	lda     PTR_READ_DEST
-	sbc     ptr2
-	sta     tmp1
-	lda     PTR_READ_DEST+1
-	sbc     ptr2+1
-	tax
+        lda     PTR_READ_DEST
+        sbc     ptr2
+        sta     tmp1
+        lda     PTR_READ_DEST+1
+        sbc     ptr2+1
+        tax
         lda     tmp1
 
         rts
diff --git a/libsrc/telestrat/write.s b/libsrc/telestrat/write.s
index 06524f749..16bc64d69 100644
--- a/libsrc/telestrat/write.s
+++ b/libsrc/telestrat/write.s
@@ -45,12 +45,12 @@ next:
 
         ;  compute nb of bytes written
         sec
-	lda     PTR_READ_DEST
-	sbc     ptr1
-	sta     tmp1
-	lda     PTR_READ_DEST+1
-	sbc     ptr1+1
-	tax
+        lda     PTR_READ_DEST
+        sbc     ptr1
+        sta     tmp1
+        lda     PTR_READ_DEST+1
+        sbc     ptr1+1
+        tax
         lda     tmp1
         rts