diff --git a/libsrc/runtime/bcast.s b/libsrc/runtime/bcast.s
new file mode 100644
index 000000000..bb37b6ec0
--- /dev/null
+++ b/libsrc/runtime/bcast.s
@@ -0,0 +1,21 @@
+;
+; acqn, 01.16.2020
+;
+; CC65 runtime: boolean cast
+;
+
+        .export         bcasta, bcastax
+
+bcastax:
+        cpx     #0
+        bne     L1
+
+bcasta:
+        tax
+        beq     L0              ; Zero already in X
+
+L1:     ldx     #0
+        lda     #1
+
+L0:     rts
+
diff --git a/libsrc/runtime/lbcast.s b/libsrc/runtime/lbcast.s
new file mode 100644
index 000000000..3dee8d956
--- /dev/null
+++ b/libsrc/runtime/lbcast.s
@@ -0,0 +1,20 @@
+;
+; acqn, 01.16.2020
+;
+; CC65 runtime: boolean cast for longs
+;
+
+        .export         bcasteax
+        .importzp       sreg, tmp1
+
+bcasteax:
+        stx     tmp1
+        ldx     #0              ; High byte of result
+        ora     tmp1
+        ora     sreg
+        ora     sreg+1
+        beq     L0
+
+        lda     #1
+L0:     rts
+
diff --git a/src/cc65/codeent.c b/src/cc65/codeent.c
index 09ca0a9c5..0e3094962 100644
--- a/src/cc65/codeent.c
+++ b/src/cc65/codeent.c
@@ -851,7 +851,9 @@ void CE_GenRegInfo (CodeEntry* E, RegContents* InputRegs)
                 if ((In->RegA & 0x0F) >= 8) {
                     Out->RegA = 0;
                 }
-            } else if (FindBoolCmpCond (E->Arg) != CMP_INV ||
+            } else if (strcmp (E->Arg, "bcastax") == 0     ||
+                       strcmp (E->Arg, "bnegax") == 0      ||
+                       FindBoolCmpCond (E->Arg) != CMP_INV ||
                        FindTosCmpCond (E->Arg) != CMP_INV) {
                 /* Result is boolean value, so X is zero on output */
                 Out->RegX = 0;
diff --git a/src/cc65/codeinfo.c b/src/cc65/codeinfo.c
index 24e27ee10..f51189293 100644
--- a/src/cc65/codeinfo.c
+++ b/src/cc65/codeinfo.c
@@ -107,6 +107,9 @@ static const FuncInfo FuncInfoTable[] = {
     { "asreax2",        REG_EAX,              REG_EAX | REG_TMP1             },
     { "asreax3",        REG_EAX,              REG_EAX | REG_TMP1             },
     { "asreax4",        REG_EAX,              REG_EAXY | REG_TMP1            },
+    { "bcasta",         REG_A,                REG_AX                         },
+    { "bcastax",        REG_AX,               REG_AX                         },
+    { "bcasteax",       REG_EAX,              REG_EAX | REG_TMP1             },
     { "bnega",          REG_A,                REG_AX                         },
     { "bnegax",         REG_AX,               REG_AX                         },
     { "bnegeax",        REG_EAX,              REG_EAX | REG_TMP1             },
diff --git a/src/cc65/coptstop.c b/src/cc65/coptstop.c
index f4f34d163..34a9b88d6 100644
--- a/src/cc65/coptstop.c
+++ b/src/cc65/coptstop.c
@@ -2328,6 +2328,7 @@ static int HarmlessCall (const char* Name)
         "asrax3",
         "asrax4",
         "asraxy",
+        "bcastax",
         "bnegax",
         "complax",
         "decax1",