diff --git a/browser/.mgnuc_opts b/browser/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/browser/.mgnuc_opts
+++ b/browser/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/bytecode/.mgnuc_opts b/bytecode/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/bytecode/.mgnuc_opts
+++ b/bytecode/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/compiler/.mgnuc_opts b/compiler/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/compiler/.mgnuc_opts
+++ b/compiler/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/deep_profiler/.mgnuc_opts b/deep_profiler/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/deep_profiler/.mgnuc_opts
+++ b/deep_profiler/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/library/.mgnuc_opts b/library/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/library/.mgnuc_opts
+++ b/library/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/mdbcomp/.mgnuc_opts b/mdbcomp/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/mdbcomp/.mgnuc_opts
+++ b/mdbcomp/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/mfilterjavac/.mgnuc_opts b/mfilterjavac/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/mfilterjavac/.mgnuc_opts
+++ b/mfilterjavac/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/profiler/.mgnuc_opts b/profiler/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/profiler/.mgnuc_opts
+++ b/profiler/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/runtime/.mgnuc_opts b/runtime/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/runtime/.mgnuc_opts
+++ b/runtime/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/slice/.mgnuc_opts b/slice/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/slice/.mgnuc_opts
+++ b/slice/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/ssdb/.mgnuc_opts b/ssdb/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/ssdb/.mgnuc_opts
+++ b/ssdb/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/tests/.mgnuc_opts b/tests/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/tests/.mgnuc_opts
+++ b/tests/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible
diff --git a/trace/.mgnuc_opts b/trace/.mgnuc_opts
index 7f823e9bf..0728c0b54 100644
--- a/trace/.mgnuc_opts
+++ b/trace/.mgnuc_opts
@@ -1 +1,2 @@
 --no-mercury-stdlib-dir
+--halt-at-warn-if-possible