diff --git a/src/company_cmd.cpp b/src/company_cmd.cpp
index bc249dd927..7d05ffb93f 100644
--- a/src/company_cmd.cpp
+++ b/src/company_cmd.cpp
@@ -260,7 +260,9 @@ static void GenerateCompanyName(Company *c)
 	StringID str;
 	Company *cc;
 	uint32 strp;
-	char buffer[100];
+	/* Reserve space for extra unicode character. We need to do this to be able
+	 * to detect too long company name. */
+	char buffer[MAX_LENGTH_COMPANY_NAME_BYTES + MAX_CHAR_LENGTH];
 
 	if (c->name_1 != STR_SV_UNNAMED) return;
 
@@ -392,7 +394,9 @@ restart:;
 		c->president_name_2 = Random();
 		c->president_name_1 = SPECSTR_PRESIDENT_NAME;
 
-		char buffer[MAX_LENGTH_PRESIDENT_NAME_BYTES + 1];
+		/* Reserve space for extra unicode character. We need to do this to be able
+		 * to detect too long president name. */
+		char buffer[MAX_LENGTH_PRESIDENT_NAME_BYTES + MAX_CHAR_LENGTH];
 		SetDParam(0, c->index);
 		GetString(buffer, STR_PRESIDENT_NAME, lastof(buffer));
 		if (strlen(buffer) >= MAX_LENGTH_PRESIDENT_NAME_BYTES) continue;
@@ -400,7 +404,8 @@ restart:;
 		Company *cc;
 		FOR_ALL_COMPANIES(cc) {
 			if (c != cc) {
-				char buffer2[MAX_LENGTH_PRESIDENT_NAME_BYTES + 2];
+				/* Reserve extra space so even overlength president names can be compared. */
+				char buffer2[MAX_LENGTH_PRESIDENT_NAME_BYTES + MAX_CHAR_LENGTH];
 				SetDParam(0, cc->index);
 				GetString(buffer2, STR_PRESIDENT_NAME, lastof(buffer2));
 				if (strcmp(buffer2, buffer) == 0) goto restart;
diff --git a/src/strings_type.h b/src/strings_type.h
index a77ad663b8..91d42d0cb3 100644
--- a/src/strings_type.h
+++ b/src/strings_type.h
@@ -17,6 +17,7 @@
  */
 typedef uint16 StringID;
 static const StringID INVALID_STRING_ID = 0xFFFF;  ///< Constant representing an invalid string
+static const int MAX_CHAR_LENGTH = 4; ///< Max. length of UTF-8 encoded unicode character
 
 enum {
 	MAX_LANG = 64, ///< Maximal number of languages supported by the game
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
index 49f462e0b1..b078fe9826 100644
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -1419,9 +1419,10 @@ struct TownNameParams {
  */
 static bool VerifyTownName(uint32 r, const TownNameParams *par)
 {
-	/* reserve space for extra unicode character and terminating '\0' */
-	char buf1[MAX_LENGTH_TOWN_NAME_BYTES + 4 + 1];
-	char buf2[MAX_LENGTH_TOWN_NAME_BYTES + 4 + 1];
+	/* Reserve space for extra unicode character. We need to do this to be able
+	 * to detect too long town name. */
+	char buf1[MAX_LENGTH_TOWN_NAME_BYTES + MAX_CHAR_LENGTH];
+	char buf2[MAX_LENGTH_TOWN_NAME_BYTES + MAX_CHAR_LENGTH];
 
 	SetDParam(0, r);
 	if (par->grf && par->grfid != 0) {