diff --git a/src/backend/regex/rege_dfa.c b/src/backend/regex/rege_dfa.c
index 957ceb8137..1db52d1005 100644
--- a/src/backend/regex/rege_dfa.c
+++ b/src/backend/regex/rege_dfa.c
@@ -499,7 +499,7 @@ newdfa(struct vars *v,
 	struct dfa *d;
 	size_t		nss = cnfa->nstates * 2;
 	int			wordsper = (cnfa->nstates + UBITS - 1) / UBITS;
-	struct smalldfa *smallwas = sml;
+	bool		ismalloced = false;
 
 	assert(cnfa != NULL && cnfa->nstates != 0);
 
@@ -514,6 +514,7 @@ newdfa(struct vars *v,
 				ERR(REG_ESPACE);
 				return NULL;
 			}
+			ismalloced = true;
 		}
 		d = &sml->dfa;
 		d->ssets = sml->ssets;
@@ -521,8 +522,8 @@ newdfa(struct vars *v,
 		d->work = &d->statesarea[nss];
 		d->outsarea = sml->outsarea;
 		d->incarea = sml->incarea;
-		d->cptsmalloced = 0;
-		d->mallocarea = (smallwas == NULL) ? (char *) sml : NULL;
+		d->ismalloced = ismalloced;
+		d->arraysmalloced = false;	/* not separately allocated, anyway */
 	}
 	else
 	{
@@ -540,8 +541,9 @@ newdfa(struct vars *v,
 											  sizeof(struct sset *));
 		d->incarea = (struct arcp *) MALLOC(nss * cnfa->ncolors *
 											sizeof(struct arcp));
-		d->cptsmalloced = 1;
-		d->mallocarea = (char *) d;
+		d->ismalloced = true;
+		d->arraysmalloced = true;
+		/* now freedfa() will behave sanely */
 		if (d->ssets == NULL || d->statesarea == NULL ||
 			d->outsarea == NULL || d->incarea == NULL)
 		{
@@ -573,7 +575,7 @@ newdfa(struct vars *v,
 static void
 freedfa(struct dfa *d)
 {
-	if (d->cptsmalloced)
+	if (d->arraysmalloced)
 	{
 		if (d->ssets != NULL)
 			FREE(d->ssets);
@@ -585,8 +587,8 @@ freedfa(struct dfa *d)
 			FREE(d->incarea);
 	}
 
-	if (d->mallocarea != NULL)
-		FREE(d->mallocarea);
+	if (d->ismalloced)
+		FREE(d);
 }
 
 /*
diff --git a/src/backend/regex/regexec.c b/src/backend/regex/regexec.c
index 2a1ef0176a..cf95989948 100644
--- a/src/backend/regex/regexec.c
+++ b/src/backend/regex/regexec.c
@@ -77,8 +77,8 @@ struct dfa
 	chr		   *lastpost;		/* location of last cache-flushed success */
 	chr		   *lastnopr;		/* location of last cache-flushed NOPROGRESS */
 	struct sset *search;		/* replacement-search-pointer memory */
-	int			cptsmalloced;	/* were the areas individually malloced? */
-	char	   *mallocarea;		/* self, or master malloced area, or NULL */
+	bool		ismalloced;		/* should this struct dfa be freed? */
+	bool		arraysmalloced; /* should its subsidiary arrays be freed? */
 };
 
 #define WORK	1				/* number of work bitvectors needed */
@@ -88,7 +88,7 @@ struct dfa
 #define FEWCOLORS	15
 struct smalldfa
 {
-	struct dfa	dfa;
+	struct dfa	dfa;			/* must be first */
 	struct sset ssets[FEWSTATES * 2];
 	unsigned	statesarea[FEWSTATES * 2 + WORK];
 	struct sset *outsarea[FEWSTATES * 2 * FEWCOLORS];