diff --git a/IncSet.c b/IncSet.c
index cee3565b..56f9c32f 100644
--- a/IncSet.c
+++ b/IncSet.c
@@ -156,7 +156,7 @@ bool IncSet_handleKey(IncSet* this, int ch, Panel* panel, IncMode_GetPanelValue
       doSearch = false;
    } else if (0 < ch && ch < 255 && isprint((unsigned char)ch)) {
       if (mode->index < INCMODE_MAX) {
-         mode->buffer[mode->index] = ch;
+         mode->buffer[mode->index] = (char) ch;
          mode->index++;
          mode->buffer[mode->index] = 0;
          if (mode->isFilter) {
diff --git a/Panel.c b/Panel.c
index 64e6d4e6..a5773d52 100644
--- a/Panel.c
+++ b/Panel.c
@@ -453,7 +453,7 @@ HandlerResult Panel_selectByTyping(Panel* this, int ch) {
       }
 
       if (len < 99) {
-         buffer[len] = ch;
+         buffer[len] = (char) ch;
          buffer[len + 1] = '\0';
       }
 
@@ -470,7 +470,7 @@ HandlerResult Panel_selectByTyping(Panel* this, int ch) {
 
          // if current word did not match,
          // retry considering the character the start of a new word.
-         buffer[0] = ch;
+         buffer[0] = (char) ch;
          buffer[1] = '\0';
       }
 
diff --git a/Panel.h b/Panel.h
index cf110c90..9bb4c77e 100644
--- a/Panel.h
+++ b/Panel.h
@@ -67,7 +67,7 @@ struct Panel_ {
    int selectedLen;
    void* eventHandlerState;
    int scrollV;
-   short scrollH;
+   int scrollH;
    bool needsRedraw;
    bool wasFocus;
    FunctionBar* currentBar;
diff --git a/configure.ac b/configure.ac
index 0824d2e3..2a4880ba 100644
--- a/configure.ac
+++ b/configure.ac
@@ -668,7 +668,8 @@ AS_VAR_IF(CACHEVAR,yes,
 AS_VAR_POPDEF([CACHEVAR])dnl
 ])dnl AX_CHECK_COMPILE_FLAGS
 
-AX_CHECK_COMPILE_FLAG([-Wnull-dereference], [AM_CFLAGS="$AM_CFLAGS -Wnull-dereference"], , [-Werror])
+AX_CHECK_COMPILE_FLAG([-Wimplicit-int-conversion], [AM_CFLAGS="$AM_CFLAGS -Wimplicit-int-conversion"], , [-Werror])
+AX_CHECK_COMPILE_FLAG([-Wnull-dereference],        [AM_CFLAGS="$AM_CFLAGS -Wnull-dereference"],        , [-Werror])
 
 AC_ARG_ENABLE([werror],
               [AS_HELP_STRING([--enable-werror],