diff --git a/elftools/elf/constants.py b/elftools/elf/constants.py
new file mode 100644
index 0000000..1c64a8f
--- /dev/null
+++ b/elftools/elf/constants.py
@@ -0,0 +1,40 @@
+# Constants and flags, placed into classes for namespacing
+
+class SHN_INDICES(object):
+    """ Special section indices
+    """
+    SHN_UNDEF=0
+    SHN_LORESERVE=0xff00
+    SHN_LOPROC=0xff00
+    SHN_HIPROC=0xff1f
+    SHN_ABS=0xfff1
+    SHN_COMMON=0xfff2
+    SHN_HIRESERVE=0xffff
+
+
+class SH_FLAGS(object):
+    """ Flag values for the sh_flags field of section headers
+    """
+    SHF_WRITE=0x1
+    SHF_ALLOC=0x2
+    SHF_EXECINSTR=0x4
+    SHF_MERGE=0x10
+    SHF_STRINGS=0x20
+    SHF_INFO_LINK=0x40
+    SHF_LINK_ORDER=0x80
+    SHF_OS_NONCONFORMING=0x100
+    SHF_GROUP=0x200
+    SHF_TLS=0x400
+    SHF_MASKOS=0x0ff00000
+    SHF_MASKPROC=0xf0000000
+
+
+class P_FLAGS(object):
+    """ Flag values for the p_flags field of program headers
+    """
+    PF_X=0x1
+    PF_W=0x2
+    PF_R=0x4
+    PF_MASKOS=0x00FF0000
+    PF_MASKPROC=0xFF000000
+
diff --git a/elftools/elf/enums.py b/elftools/elf/enums.py
index 0b76c52..0762979 100644
--- a/elftools/elf/enums.py
+++ b/elftools/elf/enums.py
@@ -82,3 +82,16 @@
     _default_='RESERVED',
 )
 
+# p_type in the program header
+ENUM_P_TYPE = dict(
+    PT_NULL=0,
+    PT_LOAD=1,
+    PT_DYNAMIC=2,
+    PT_INTERP=3,
+    PT_NOTE=4,
+    PT_SHLIB=5,
+    PT_PHDR=6,
+    PT_LOPROC=0x70000000,
+    PT_HIPROC=0x7fffffff,
+)
+
diff --git a/elftools/elf/flags.py b/elftools/elf/flags.py
deleted file mode 100644
index 32a1ed3..0000000
--- a/elftools/elf/flags.py
+++ /dev/null
@@ -1,16 +0,0 @@
-# Flag values, placed into classes for namespacing
-
-class SH_FLAGS(object):
-    SHF_WRITE=0x1
-    SHF_ALLOC=0x2
-    SHF_EXECINSTR=0x4
-    SHF_MERGE=0x10
-    SHF_STRINGS=0x20
-    SHF_INFO_LINK=0x40
-    SHF_LINK_ORDER=0x80
-    SHF_OS_NONCONFORMING=0x100
-    SHF_GROUP=0x200
-    SHF_TLS=0x400
-    SHF_MASKOS=0x0ff00000
-    SHF_MASKPROC=0xf0000000
-
diff --git a/elftools/elf/structs.py b/elftools/elf/structs.py
index 090a8a9..8c610dc 100644
--- a/elftools/elf/structs.py
+++ b/elftools/elf/structs.py
@@ -36,6 +36,7 @@
             self.Elf_sxword = SBInt32 if self.elfclass == 32 else SBInt64
         
         self._create_ehdr()
+        self._create_phdr()
         self._create_shdr()
         self._create_sym()
     
@@ -63,6 +64,30 @@
             self.Elf_half('e_shstrndx'),
         )
     
+    def _create_phdr(self):
+        if self.elfclass == 32:
+            self.Elf_Phdr = Struct('Elf_Phdr',
+                Enum(self.Elf_word('p_type'), **ENUM_P_TYPE),
+                self.Elf_offset('p_offset'),
+                self.Elf_addr('p_vaddr'),
+                self.Elf_addr('p_paddr'),
+                self.Elf_word('p_filesz'),
+                self.Elf_word('p_memsz'),
+                self.Elf_word('p_flags'),
+                self.Elf_word('p_align'),
+            )
+        else:
+            self.Elf_Phdr = Struct('Elf_Phdr',
+                Enum(self.Elf_word('p_type'), **ENUM_P_TYPE),
+                self.Elf_word('p_flags'),
+                self.Elf_offset('p_offset'),
+                self.Elf_addr('p_vaddr'),
+                self.Elf_addr('p_paddr'),
+                self.Elf_word('p_filesz'),
+                self.Elf_word('p_memsz'),
+                self.Elf_word('p_align'),
+            )   
+        
     def _create_shdr(self):
         self.Elf_Shdr = Struct('Elf_Shdr',
             self.Elf_word('sh_name'),