Index: t/pmc/timer.t
===================================================================
--- t/pmc/timer.t	(revision 37094)
+++ t/pmc/timer.t	(working copy)
@@ -153,7 +153,7 @@
 ok 2
 OUT
 
-    my @todo = $ENV{TEST_PROG_ARGS} =~ /-j/ ?
+    my @todo = $ENV{TEST_PROG_ARGS} =~ /--runcore=jit/ ?
        ( todo => 'RT #49718, add scheduler features to JIT' ) : ();
     pasm_output_is( <<'CODE', <<'OUT', "Timer setup - initializer/start/repeat" , @todo );
 .include "timer.pasm"
Index: t/pmc/threads.t
===================================================================
--- t/pmc/threads.t	(revision 37094)
+++ t/pmc/threads.t	(working copy)
@@ -733,9 +733,9 @@
 my @todo;
 
 if ( $ENV{TEST_PROG_ARGS} ) {
-    push @todo, ( todo => 'Broken with CGP' ) if $ENV{TEST_PROG_ARGS} =~ /-C/;
-    push @todo, ( todo => 'Broken with JIT' ) if $ENV{TEST_PROG_ARGS} =~ /-j/;
-    push @todo, ( todo => 'Broken with -S' )  if $ENV{TEST_PROG_ARGS} =~ /-S/;
+    push @todo, ( todo => 'Broken with CGP' ) if $ENV{TEST_PROG_ARGS} =~ /--runcore=cgp/;
+    push @todo, ( todo => 'Broken with JIT' ) if $ENV{TEST_PROG_ARGS} =~ /--runcore=jit/;
+    push @todo, ( todo => 'Broken with switch core' )  if $ENV{TEST_PROG_ARGS} =~ /--runcore=switch/;
 }
 pir_output_unlike( <<'CODE', qr/not/, "globals + constant table subs issue", @todo );
 .namespace [ 'Foo' ]
Index: t/pmc/nci.t
===================================================================
--- t/pmc/nci.t	(revision 37094)
+++ t/pmc/nci.t	(working copy)
@@ -1372,7 +1372,7 @@
 OUTPUT
 
   # Tests with callback functions
-  my @todo = $ENV{TEST_PROG_ARGS} =~ /-j/ ?
+  my @todo = $ENV{TEST_PROG_ARGS} =~ /--runcore=jit/ ?
     ( todo => 'RT #49718, add scheduler tasks to JIT' ) : ();
 
   pasm_output_is( <<'CODE', <<'OUTPUT', "nci_cb_C1 - PASM", @todo );
Index: t/dynoplibs/myops.t
===================================================================
--- t/dynoplibs/myops.t	(revision 37094)
+++ t/dynoplibs/myops.t	(working copy)
@@ -67,7 +67,7 @@
     my @todo;
 
     if ( $ENV{TEST_PROG_ARGS} ) {
-        @todo = ( todo => 'broken with -j' ) if $ENV{TEST_PROG_ARGS} =~ /-j/;
+        @todo = ( todo => 'broken with JIT' ) if $ENV{TEST_PROG_ARGS} =~ /--runcore=jit/;
     }
 
     my $quine = <<'END_PASM';
@@ -77,7 +77,7 @@
     pasm_output_is( $quine, $quine, 'a short cheating quine', @todo );
 }
 
-    my @todo = $ENV{TEST_PROG_ARGS} =~ /-j/ ?
+    my @todo = $ENV{TEST_PROG_ARGS} =~ /--runcore=jit/ ?
        ( todo => 'RT #49718, add scheduler features to JIT' ) : ();
 
 pir_output_is( << 'CODE', << 'OUTPUT', "one alarm", @todo );
@@ -112,9 +112,9 @@
 
 SKIP: {
     skip "three alarms, infinite loop under mingw32", 2 if $is_mingw;
-    skip "dynops weird in CGP with events", 2 if $ENV{TEST_PROG_ARGS} =~ /-g/;
+    skip "dynops weird in CGP with events", 2 if $ENV{TEST_PROG_ARGS} =~ /--runcore=cgoto/;
 
-    my @todo = $ENV{TEST_PROG_ARGS} =~ /-j/ ?
+    my @todo = $ENV{TEST_PROG_ARGS} =~ /--runcore=jit/ ?
        ( todo => 'RT #49718, add scheduler features to JIT' ) : ();
 
     pir_output_like( << 'CODE', << 'OUTPUT', "three alarm", @todo );
Index: t/examples/japh.t
===================================================================
--- t/examples/japh.t	(revision 37094)
+++ t/examples/japh.t	(working copy)
@@ -38,8 +38,8 @@
 if ( $PConfig{intvalsize} == 8 ) {
     $todo{2} = 'works only with 32-bit integer values';
 }
-if ( defined( $ENV{TEST_PROG_ARGS}) && $ENV{TEST_PROG_ARGS} =~ /-j/ ) {
-    $todo{4} = 'broken with -j';
+if ( defined( $ENV{TEST_PROG_ARGS}) && $ENV{TEST_PROG_ARGS} =~ /--runcore=jit/ ) {
+    $todo{4} = 'broken with JIT';
 }
 
 # run all tests and tell about todoness
Index: t/op/trans.t
===================================================================
--- t/op/trans.t	(revision 37094)
+++ t/op/trans.t	(working copy)
@@ -266,7 +266,7 @@
 OUTPUT
 
 my $runcore = $ENV{TEST_PROG_ARGS} || '';
-my @todo    = ( $runcore =~ /j/ ? ( todo => 'broken under JIT TT #201' ) : () );
+my @todo    = ( $runcore =~ /--runcore=jit/ ? ( todo => 'broken under JIT TT #201' ) : () );
 
 pasm_output_is( <<"CODE", <<OUTPUT, 'atan2', @todo );
         .include 'include/fp_equality.pasm'
Index: t/op/debuginfo.t
===================================================================
--- t/op/debuginfo.t	(revision 37094)
+++ t/op/debuginfo.t	(working copy)
@@ -24,11 +24,11 @@
 =cut
 
 $ENV{TEST_PROG_ARGS} ||= '';
-my $nolineno = $ENV{TEST_PROG_ARGS} =~ /-f/
+my $nolineno = $ENV{TEST_PROG_ARGS} =~ /--runcore=(fast|cgoto)/
     ? "\\(unknown file\\)\n-1" : "debuginfo_\\d+\\.pasm\n\\d";
 
 SKIP: {
-skip "disabled on fast-core",1 if $ENV{TEST_PROG_ARGS} =~ /[^-]?-[fg]/;
+skip "disabled on fast-core",1 if $ENV{TEST_PROG_ARGS} =~ /--runcore=(fast|cgoto)/;
 
 pasm_output_like( <<'CODE', <<"OUTPUT", "getline, getfile" );
 .pcc_sub main:
@@ -164,11 +164,11 @@
 called from Sub 'main' pc (\d+|-1) \(.*?:(\d+|-1)\)$/
 OUTPUT
 
-$nolineno = $ENV{TEST_PROG_ARGS} =~ /-f/
+$nolineno = $ENV{TEST_PROG_ARGS} =~ /--runcore=fast/
     ? '\(\(unknown file\):-1\)' : '\(xyz.pir:126\)';
 
 SKIP: {
-skip "disabled on this core",2 if $ENV{TEST_PROG_ARGS} =~ /[^-]?-[fgjS]/;
+skip "disabled on this core",2 if $ENV{TEST_PROG_ARGS} =~ /--runcore=(fast|cgoto|jit|switch)/;
 
 # See "RT #43269 and .annotate
 pir_error_output_like( <<'CODE', <<"OUTPUT", "setfile and setline" );
@@ -183,7 +183,7 @@
 /$nolineno/
 OUTPUT
 
-$nolineno = $ENV{TEST_PROG_ARGS} =~ /-f/
+$nolineno = $ENV{TEST_PROG_ARGS} =~ /--runcore=(fast|cgoto|jit|switch)/
     ? '\(\(unknown file\):-1\)' : '\(foo.p6:128\)';
 # See "RT #43269 and .annotate
 pir_error_output_like( <<'CODE', <<"OUTPUT", "setfile and setline" );
Index: t/op/bitwise.t
===================================================================
--- t/op/bitwise.t	(revision 37094)
+++ t/op/bitwise.t	(working copy)
@@ -509,7 +509,7 @@
     my @todo;
     @todo = ( todo => 'broken with JIT (RT #43245)' )
         if ( defined $ENV{TEST_PROG_ARGS} and 
-            $ENV{TEST_PROG_ARGS} =~ /-j/ );
+            $ENV{TEST_PROG_ARGS} =~ /--runcore=jit/ );
 
     pir_output_is( <<'CODE', <<'OUT', "I-reg shl and PMC shl are consistent", @todo );
 ## The PMC shl op will promote Integer to Bigint when needed.  We can't stuff a
Index: t/op/01-parse_ops.t
===================================================================
--- t/op/01-parse_ops.t	(revision 37094)
+++ t/op/01-parse_ops.t	(working copy)
@@ -77,7 +77,7 @@
     if $ENV{TEST_PROG_ARGS} =~ /--runcore=jit/;
 
 plan skip_all => 'IMCC cannot do parse-only with switched core'
-    if $ENV{TEST_PROG_ARGS} =~ /-S/;
+    if $ENV{TEST_PROG_ARGS} =~ /--runcore=switch/;
 
 plan tests => scalar keys %cmds;