diff --git a/.github/workflows/root-ci-config/build_root.py b/.github/workflows/root-ci-config/build_root.py
index ed9303effd695..17f890d5fba48 100755
--- a/.github/workflows/root-ci-config/build_root.py
+++ b/.github/workflows/root-ci-config/build_root.py
@@ -317,7 +317,7 @@ def run_ctest(extra_ctest_flags: str) -> int:
     builddir = os.path.join(WORKDIR, "build")
     ctest_result = subprocess_with_log(f"""
         cd '{builddir}'
-        ctest --output-on-failure --parallel {os.cpu_count()} --output-junit TestResults.xml {extra_ctest_flags}
+        ctest -R "roottest-root-hist-h2root" --output-on-failure --parallel {os.cpu_count()} --output-junit TestResults.xml {extra_ctest_flags}
     """)
 
     return ctest_result
diff --git a/.github/workflows/root-ci-config/buildconfig/mac14.txt b/.github/workflows/root-ci-config/buildconfig/mac14.txt
index 56115d057e880..6a05790d73c7b 100644
--- a/.github/workflows/root-ci-config/buildconfig/mac14.txt
+++ b/.github/workflows/root-ci-config/buildconfig/mac14.txt
@@ -26,7 +26,6 @@ builtin_xxhash=ON
 builtin_zeromq=ON
 builtin_zstd=ON
 cocoa=ON
-fortran=OFF
 minuit2_omp=OFF
 test_distrdf_dask=OFF
 test_distrdf_pyspark=OFF
diff --git a/main/CMakeLists.txt b/main/CMakeLists.txt
index 98e50fd87e853..a7b88e0acc487 100644
--- a/main/CMakeLists.txt
+++ b/main/CMakeLists.txt
@@ -53,7 +53,6 @@ generateHeader(hadd
 
 if(fortran AND CMAKE_Fortran_COMPILER)
   ROOT_EXECUTABLE(g2root g2root.f LIBRARIES minicern CMAKENOEXPORT)
-  set_target_properties(g2root PROPERTIES COMPILE_FLAGS "-w")
   ROOT_EXECUTABLE(h2root h2root.cxx LIBRARIES Core RIO Net Hist Graf Graf3d Gpad Tree Matrix MathCore Thread minicern CMAKENOEXPORT)
 
   # This is needed in particular for macOS, where the path of the GNU Fortran
diff --git a/main/src/h2root.cxx b/main/src/h2root.cxx
index 87133310483a9..4eae29a72d0aa 100644
--- a/main/src/h2root.cxx
+++ b/main/src/h2root.cxx
@@ -479,9 +479,9 @@ void convert_1d(Int_t id)
    else        snprintf(idname,128,"h_%d",-id);
    hnoent(id,nentries);
 #ifndef WIN32
-   hgive(id,chtitl,ncx,xmin,xmax,ncy,ymin,ymax,nwt,idb,80);
+   hgive(id,chtitl,ncx,xmin,xmax,ncy,ymin,ymax,nwt,idb,128);
 #else
-   hgive(id,chtitl,80,ncx,xmin,xmax,ncy,ymin,ymax,nwt,idb);
+   hgive(id,chtitl,128,ncx,xmin,xmax,ncy,ymin,ymax,nwt,idb);
 #endif
    chtitl[4*nwt] = 0;
    TH1F *h1;
diff --git a/misc/minicern/CMakeLists.txt b/misc/minicern/CMakeLists.txt
index 66542f68ce3cb..2a93967abe68e 100644
--- a/misc/minicern/CMakeLists.txt
+++ b/misc/minicern/CMakeLists.txt
@@ -12,9 +12,5 @@ ROOT_LINKER_LIBRARY(minicern *.c *.f TYPE STATIC)
 set_property(TARGET minicern PROPERTY POSITION_INDEPENDENT_CODE ON)
 target_link_libraries(minicern ${CMAKE_Fortran_IMPLICIT_LINK_LIBRARIES})
 
-# Disable optimization since it some cases was causing crashes.
-# Disable warnings, since what has worked for 40 years...
-# (see https://sft.its.cern.ch/jira/browse/ROOT-9179 for the warnings)
-set_target_properties(minicern PROPERTIES COMPILE_FLAGS "-O0 -w")
-# set_target_properties(minicern PROPERTIES COMPILE_FLAGS "-fsanitize=undefined -fsanitize=address")
-# target_link_options(minicern BEFORE PUBLIC -fsanitize=undefined PUBLIC -fsanitize=address)
+# set_target_properties(minicern PROPERTIES COMPILE_FLAGS "-fsanitize=undefined -fsanitize=address") # TODO enabling this shows issues
+# target_link_options(minicern BEFORE PUBLIC -fsanitize=undefined PUBLIC -fsanitize=address) # TODO enabling this shows issues
diff --git a/misc/minicern/src/hbook.f b/misc/minicern/src/hbook.f
index 522c731686169..9311a6e8b84ad 100644
--- a/misc/minicern/src/hbook.f
+++ b/misc/minicern/src/hbook.f
@@ -305,6 +305,11 @@ SUBROUTINE HRFILE(LUN,CHDIR,CHOPT)
       DIMENSION IOPT(6)
       EQUIVALENCE (IOPTN,IOPT(1)),(IOPTG,IOPT(2)),(IOPTQ,IOPT(3))
       EQUIVALENCE (IOPTM,IOPT(4)),(IOPTO,IOPT(5)),(IOPTE,IOPT(6))
+
+      ! --- new local temporaries for safe short-character assignment
+      CHARACTER*16 CHTMP
+      INTEGER NCHR
+
       IF(NCHTOP.GE.MXFILES)THEN
          print*, 'Too many open files','HRFILE',LUN
          GO TO 99
@@ -356,14 +361,28 @@ SUBROUTINE HRFILE(LUN,CHDIR,CHOPT)
       ENDIF
       IF(IQUEST(1).NE.0)RETURN
       NCHTOP=NCHTOP+1
-      CHTOP(NCHTOP)=CHDIR
+
+      ! ---- safe assignment of CHTOP(NCHTOP) from CHDIR (CHTOP is 16 chars)
+      CHTMP = ' '
+      NCHR = LEN_TRIM(CHDIR)
+      IF (NCHR .GT. 16) THEN
+         CHTMP = CHDIR(1:16)
+      ELSE
+         IF (NCHR .GT. 0) THEN
+            CHTMP(1:NCHR) = CHDIR(1:NCHR)
+         ENDIF
+      ENDIF
+      CHTOP(NCHTOP) = CHTMP
+
       ICHLUN(NCHTOP)=0
       IF(IOPTG.EQ.0)THEN
          ICHTOP(NCHTOP)=LUN
          ICHTYP(NCHTOP)=NWK
          HFNAME(NCHTOP)=CHDIR
       ELSE
-         ICHTOP(NCHTOP)=-LOCF(LUN)
+         ! ---- replaced non-portable pointer storage: do NOT store LOCF() into INTEGER
+         !      store a safe negative marker instead (unique per top index)
+         ICHTOP(NCHTOP) = -NCHTOP
          ICHTYP(NCHTOP)=0
          IF(IOPTM.EQ.0)THEN
             HFNAME(NCHTOP)='Global section - '//CHDIR