diff --git a/src/fish.cpp b/src/fish.cpp
index eeafa5591..143d338f0 100644
--- a/src/fish.cpp
+++ b/src/fish.cpp
@@ -408,7 +408,7 @@ int main(int argc, char **argv) {
         // TODO: Remove this once we're confident that not blocking/unblocking every signal around
         // some critical sections is no longer necessary.
         env_var_t fish_no_signal_block = env_get_string(L"FISH_NO_SIGNAL_BLOCK");
-        if (!fish_no_signal_block.missing()) ignore_signal_block = true;
+        if (!fish_no_signal_block.missing_or_empty() && !from_string<bool>(fish_no_signal_block)) ignore_signal_block = false;
 
         // Stomp the exit status of any initialization commands (issue #635).
         proc_set_last_status(STATUS_BUILTIN_OK);
diff --git a/src/signal.cpp b/src/signal.cpp
index 8fe2bd2d8..8c4f994ae 100644
--- a/src/signal.cpp
+++ b/src/signal.cpp
@@ -17,7 +17,7 @@
 #include "wutil.h"  // IWYU pragma: keep
 
 // This is a temporary var while we explore whether signal_block() and friends is needed.
-bool ignore_signal_block = false;
+bool ignore_signal_block = true;
 
 /// Struct describing an entry for the lookup table used to convert between signal names and signal
 /// ids, etc.