diff --git a/Documentation/config.txt b/Documentation/config.txt
index eb66a11975..b25f1c0dc4 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -909,6 +909,12 @@ relatively high IO latencies.  When enabled, Git will do the
 index comparison to the filesystem data in parallel, allowing
 overlapping IO's.  Defaults to true.
 
+core.unsetenvvars::
+	EXPERIMENTAL, Windows-only: comma-separated list of environment
+	variables' names that need to be unset before spawning any other
+	process. Defaults to `PERL5LIB` to account for the fact that Git
+	for Windows insists on using its own Perl interpreter.
+
 core.createObject::
 	You can set this to 'link', in which case a hardlink followed by
 	a delete of the source are used to make sure that object creation
diff --git a/cache.h b/cache.h
index 4d014541ab..f49d9fbac8 100644
--- a/cache.h
+++ b/cache.h
@@ -901,14 +901,6 @@ int use_optional_locks(void);
 extern char comment_line_char;
 extern int auto_comment_line_char;
 
-/* Windows only */
-enum hide_dotfiles_type {
-	HIDE_DOTFILES_FALSE = 0,
-	HIDE_DOTFILES_TRUE,
-	HIDE_DOTFILES_DOTGITONLY
-};
-extern enum hide_dotfiles_type hide_dotfiles;
-
 enum log_refs_config {
 	LOG_REFS_UNSET = -1,
 	LOG_REFS_NONE = 0,
diff --git a/compat/mingw.c b/compat/mingw.c
index 858ca14a57..00191fe9db 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -202,6 +202,35 @@ static int ask_yes_no_if_possible(const char *format, ...)
 	}
 }
 
+/* Windows only */
+enum hide_dotfiles_type {
+	HIDE_DOTFILES_FALSE = 0,
+	HIDE_DOTFILES_TRUE,
+	HIDE_DOTFILES_DOTGITONLY
+};
+
+static enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
+static char *unset_environment_variables;
+
+int mingw_core_config(const char *var, const char *value, void *cb)
+{
+	if (!strcmp(var, "core.hidedotfiles")) {
+		if (value && !strcasecmp(value, "dotgitonly"))
+			hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
+		else
+			hide_dotfiles = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.unsetenvvars")) {
+		free(unset_environment_variables);
+		unset_environment_variables = xstrdup(value);
+		return 0;
+	}
+
+	return 0;
+}
+
 int mingw_unlink(const char *pathname)
 {
 	int ret, tries = 0;
@@ -1080,6 +1109,27 @@ static wchar_t *make_environment_block(char **deltaenv)
 	return wenvblk;
 }
 
+static void do_unset_environment_variables(void)
+{
+	static int done;
+	char *p = unset_environment_variables;
+
+	if (done || !p)
+		return;
+	done = 1;
+
+	for (;;) {
+		char *comma = strchr(p, ',');
+
+		if (comma)
+			*comma = '\0';
+		unsetenv(p);
+		if (!comma)
+			break;
+		p = comma + 1;
+	}
+}
+
 struct pinfo_t {
 	struct pinfo_t *next;
 	pid_t pid;
@@ -1098,9 +1148,12 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 	wchar_t wcmd[MAX_PATH], wdir[MAX_PATH], *wargs, *wenvblk = NULL;
 	unsigned flags = CREATE_UNICODE_ENVIRONMENT;
 	BOOL ret;
+	HANDLE cons;
+
+	do_unset_environment_variables();
 
 	/* Determine whether or not we are associated to a console */
-	HANDLE cons = CreateFile("CONOUT$", GENERIC_WRITE,
+	cons = CreateFile("CONOUT$", GENERIC_WRITE,
 			FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
 			FILE_ATTRIBUTE_NORMAL, NULL);
 	if (cons == INVALID_HANDLE_VALUE) {
@@ -2291,6 +2344,8 @@ void mingw_startup(void)
 	/* fix Windows specific environment settings */
 	setup_windows_environment();
 
+	unset_environment_variables = xstrdup("PERL5LIB");
+
 	/* initialize critical section for waitpid pinfo_t list */
 	InitializeCriticalSection(&pinfo_cs);
 
diff --git a/compat/mingw.h b/compat/mingw.h
index 571019d0bd..908279decc 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -11,6 +11,9 @@ typedef _sigset_t sigset_t;
 #undef _POSIX_THREAD_SAFE_FUNCTIONS
 #endif
 
+extern int mingw_core_config(const char *var, const char *value, void *cb);
+#define platform_core_config mingw_core_config
+
 /*
  * things that are not available in header files
  */
diff --git a/config.c b/config.c
index 3461993f0a..221de4bc0f 100644
--- a/config.c
+++ b/config.c
@@ -1093,7 +1093,7 @@ int git_config_color(char *dest, const char *var, const char *value)
 	return 0;
 }
 
-static int git_default_core_config(const char *var, const char *value)
+static int git_default_core_config(const char *var, const char *value, void *cb)
 {
 	/* This needs a better name */
 	if (!strcmp(var, "core.filemode")) {
@@ -1344,14 +1344,6 @@ static int git_default_core_config(const char *var, const char *value)
 		return 0;
 	}
 
-	if (!strcmp(var, "core.hidedotfiles")) {
-		if (value && !strcasecmp(value, "dotgitonly"))
-			hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
-		else
-			hide_dotfiles = git_config_bool(var, value);
-		return 0;
-	}
-
 	if (!strcmp(var, "core.partialclonefilter")) {
 		return git_config_string(&core_partial_clone_filter_default,
 					 var, value);
@@ -1363,7 +1355,7 @@ static int git_default_core_config(const char *var, const char *value)
 	}
 
 	/* Add other config variables here and to Documentation/config.txt. */
-	return 0;
+	return platform_core_config(var, value, cb);
 }
 
 static int git_default_i18n_config(const char *var, const char *value)
@@ -1448,13 +1440,13 @@ static int git_default_mailmap_config(const char *var, const char *value)
 	return 0;
 }
 
-int git_default_config(const char *var, const char *value, void *dummy)
+int git_default_config(const char *var, const char *value, void *cb)
 {
 	if (starts_with(var, "core."))
-		return git_default_core_config(var, value);
+		return git_default_core_config(var, value, cb);
 
 	if (starts_with(var, "user."))
-		return git_ident_config(var, value, dummy);
+		return git_ident_config(var, value, cb);
 
 	if (starts_with(var, "i18n."))
 		return git_default_i18n_config(var, value);
diff --git a/environment.c b/environment.c
index 3f3c8746c2..30ecd4e784 100644
--- a/environment.c
+++ b/environment.c
@@ -71,7 +71,6 @@ int core_apply_sparse_checkout;
 int merge_log_config = -1;
 int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
 unsigned long pack_size_limit_cfg;
-enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
 enum log_refs_config log_all_ref_updates = LOG_REFS_UNSET;
 
 #ifndef PROTECT_HFS_DEFAULT
diff --git a/git-compat-util.h b/git-compat-util.h
index 5f2e90932f..7513ec4949 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -342,6 +342,14 @@ typedef uintmax_t timestamp_t;
 #define _PATH_DEFPATH "/usr/local/bin:/usr/bin:/bin"
 #endif
 
+#ifndef platform_core_config
+static inline int noop_core_config(const char *var, const char *value, void *cb)
+{
+	return 0;
+}
+#define platform_core_config noop_core_config
+#endif
+
 #ifndef has_dos_drive_prefix
 static inline int git_has_dos_drive_prefix(const char *path)
 {
diff --git a/t/t0029-core-unsetenvvars.sh b/t/t0029-core-unsetenvvars.sh
new file mode 100755
index 0000000000..24ce46a6ea
--- /dev/null
+++ b/t/t0029-core-unsetenvvars.sh
@@ -0,0 +1,30 @@
+#!/bin/sh
+
+test_description='test the Windows-only core.unsetenvvars setting'
+
+. ./test-lib.sh
+
+if ! test_have_prereq MINGW
+then
+	skip_all='skipping Windows-specific tests'
+	test_done
+fi
+
+test_expect_success 'setup' '
+	mkdir -p "$TRASH_DIRECTORY/.git/hooks" &&
+	write_script "$TRASH_DIRECTORY/.git/hooks/pre-commit" <<-\EOF
+	echo $HOBBES >&2
+	EOF
+'
+
+test_expect_success 'core.unsetenvvars works' '
+	HOBBES=Calvin &&
+	export HOBBES &&
+	git commit --allow-empty -m with 2>err &&
+	grep Calvin err &&
+	git -c core.unsetenvvars=FINDUS,HOBBES,CALVIN \
+		commit --allow-empty -m without 2>err &&
+	! grep Calvin err
+'
+
+test_done