diff --git a/src/parser.cpp b/src/parser.cpp
index d44bdab18..bdbc0ac37 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -26,7 +26,6 @@
 #include "parse_util.h"
 #include "proc.h"
 #include "reader.h"
-#include "sanity.h"
 #include "signal.h"
 #include "wutil.h"  // IWYU pragma: keep
 
diff --git a/src/proc.cpp b/src/proc.cpp
index 90e1a57c1..54c5b7df4 100644
--- a/src/proc.cpp
+++ b/src/proc.cpp
@@ -50,7 +50,6 @@
 #include "parser.h"
 #include "proc.h"
 #include "reader.h"
-#include "sanity.h"
 #include "signal.h"
 #include "wcstringutil.h"
 #include "wutil.h"  // IWYU pragma: keep
diff --git a/src/reader.cpp b/src/reader.cpp
index c1b45672d..1714040d9 100644
--- a/src/reader.cpp
+++ b/src/reader.cpp
@@ -71,7 +71,6 @@
 #include "parser.h"
 #include "proc.h"
 #include "reader.h"
-#include "sanity.h"
 #include "screen.h"
 #include "signal.h"
 #include "termsize.h"
diff --git a/src/sanity.cpp b/src/sanity.cpp
deleted file mode 100644
index a87dd6c64..000000000
--- a/src/sanity.cpp
+++ /dev/null
@@ -1,36 +0,0 @@
-// Functions for performing sanity checks on the program state.
-#include "config.h"  // IWYU pragma: keep
-
-#include "sanity.h"
-
-#include <unistd.h>
-
-#include "common.h"
-#include "fallback.h"  // IWYU pragma: keep
-#include "flog.h"
-#include "global_safety.h"
-#include "history.h"
-#include "kill.h"
-#include "proc.h"
-#include "reader.h"
-
-/// Status from earlier sanity checks.
-static relaxed_atomic_bool_t insane{false};
-
-void sanity_lose() {
-    FLOG(error, _(L"Errors detected, shutting down. Break on sanity_lose() to debug."));
-    insane = true;
-}
-
-void validate_pointer(const void *ptr, const wchar_t *err, int null_ok) {
-    // Test if the pointer data crosses a segment boundary.
-    if ((0x00000003L & reinterpret_cast<intptr_t>(ptr)) != 0) {
-        FLOGF(error, _(L"The pointer '%ls' is invalid"), err);
-        sanity_lose();
-    }
-
-    if ((!null_ok) && (ptr == nullptr)) {
-        FLOGF(error, _(L"The pointer '%ls' is null"), err);
-        sanity_lose();
-    }
-}
diff --git a/src/sanity.h b/src/sanity.h
deleted file mode 100644
index e156dd28d..000000000
--- a/src/sanity.h
+++ /dev/null
@@ -1,15 +0,0 @@
-// Prototypes for functions for performing sanity checks on the program state.
-#ifndef FISH_SANITY_H
-#define FISH_SANITY_H
-
-/// Call this function to tell the program it is not in a sane state.
-void sanity_lose();
-
-/// Try and determine if ptr is a valid pointer. If not, loose sanity.
-///
-/// \param ptr The pointer to validate
-/// \param err A description of what the pointer refers to, for use in error messages
-/// \param null_ok Whether the pointer is allowed to point to 0
-void validate_pointer(const void *ptr, const wchar_t *err, int null_ok);
-
-#endif