diff -Nuar a/build/autoconf/icu.m4 b/build/autoconf/icu.m4
--- a/build/autoconf/icu.m4	2017-09-14 23:15:53.000000000 +0300
+++ b/build/autoconf/icu.m4	2018-01-19 18:45:55.713445653 +0300
@@ -15,7 +15,7 @@
     MOZ_SYSTEM_ICU=1)
 
 if test -n "$MOZ_SYSTEM_ICU"; then
-    PKG_CHECK_MODULES(MOZ_ICU, icu-i18n >= 59.1)
+    PKG_CHECK_MODULES(MOZ_ICU, icu-i18n >= 58.2)
     CFLAGS="$CFLAGS $MOZ_ICU_CFLAGS"
     CXXFLAGS="$CXXFLAGS $MOZ_ICU_CFLAGS"
 fi
diff -Nuar a/old-configure b/old-configure
--- a/old-configure	2018-01-19 02:55:53.000000000 +0300
+++ b/old-configure	2018-01-19 18:45:13.792448678 +0300
@@ -17589,29 +17589,29 @@
   else
      PKG_CONFIG_MIN_VERSION=0.9.0
      if $PKG_CONFIG --atleast-pkgconfig-version $PKG_CONFIG_MIN_VERSION; then
-        echo $ac_n "checking for icu-i18n >= 59.1""... $ac_c" 1>&6
-echo "configure:17594: checking for icu-i18n >= 59.1" >&5
+        echo $ac_n "checking for icu-i18n >= 58.2""... $ac_c" 1>&6
+echo "configure:17594: checking for icu-i18n >= 58.2" >&5
 
-        if $PKG_CONFIG --exists "icu-i18n >= 59.1" ; then
+        if $PKG_CONFIG --exists "icu-i18n >= 58.2" ; then
             echo "$ac_t""yes" 1>&6
             succeeded=yes
 
             echo $ac_n "checking MOZ_ICU_CFLAGS""... $ac_c" 1>&6
 echo "configure:17601: checking MOZ_ICU_CFLAGS" >&5
-            MOZ_ICU_CFLAGS=`$PKG_CONFIG --cflags "icu-i18n >= 59.1"`
+            MOZ_ICU_CFLAGS=`$PKG_CONFIG --cflags "icu-i18n >= 58.2"`
             echo "$ac_t""$MOZ_ICU_CFLAGS" 1>&6
 
             echo $ac_n "checking MOZ_ICU_LIBS""... $ac_c" 1>&6
 echo "configure:17606: checking MOZ_ICU_LIBS" >&5
             ## Remove evil flags like -Wl,--export-dynamic
-            MOZ_ICU_LIBS="`$PKG_CONFIG --libs \"icu-i18n >= 59.1\" |sed s/-Wl,--export-dynamic//g`"
+            MOZ_ICU_LIBS="`$PKG_CONFIG --libs \"icu-i18n >= 58.2\" |sed s/-Wl,--export-dynamic//g`"
             echo "$ac_t""$MOZ_ICU_LIBS" 1>&6
         else
             MOZ_ICU_CFLAGS=""
             MOZ_ICU_LIBS=""
             ## If we have a custom action on failure, don't print errors, but 
             ## do set a variable so people can do so.
-            MOZ_ICU_PKG_ERRORS=`$PKG_CONFIG --errors-to-stdout --print-errors "icu-i18n >= 59.1"`
+            MOZ_ICU_PKG_ERRORS=`$PKG_CONFIG --errors-to-stdout --print-errors "icu-i18n >= 58.2"`
             echo $MOZ_ICU_PKG_ERRORS
         fi
 
@@ -17627,7 +17627,7 @@
      :
   else
      if test "$COMPILE_ENVIRONMENT"; then 
-       { echo "configure: error: Library requirements (icu-i18n >= 59.1) not met; consider adjusting the PKG_CONFIG_PATH environment variable if your libraries are in a nonstandard prefix so pkg-config can find them." 1>&2; echo "configure: error: Library requirements (icu-i18n >= 59.1) not met; consider adjusting the PKG_CONFIG_PATH environment variable if your libraries are in a nonstandard prefix so pkg-config can find them." 1>&5; exit 1; }
+       { echo "configure: error: Library requirements (icu-i18n >= 58.2) not met; consider adjusting the PKG_CONFIG_PATH environment variable if your libraries are in a nonstandard prefix so pkg-config can find them." 1>&2; echo "configure: error: Library requirements (icu-i18n >= 58.2) not met; consider adjusting the PKG_CONFIG_PATH environment variable if your libraries are in a nonstandard prefix so pkg-config can find them." 1>&5; exit 1; }
      fi
   fi